Source
General

• Level cap will be raised to 80, prof to 450.
• New talents and extending of trees for all classes.
• No new races have been announced, nor are they planned .
• There will be a closed beta for the expansion.
  
• You can use your Outland flying mount, and new flying mounts will be available.
• Players will unlock their flying mount at level 77.
• There are some changes in the works for the UI along the lines of Outfitter and Item Rack.
• Possible addition of a threat meter to the game.
• The Ashbringer storyline will be continued.
• There will be a world event as the Lich King moves against the Horde and Alliance.
• New profession added: Inscription - able to modify existing spells and abilities.
• The mounts available to buy in Wrath will probably be able to take passengers. These mounts will also work in the old world (Provided they are land mounts), so players can give low-level characters a ride! The new mounts will also be slightly faster, around the speed of the Armored Netherdrakes.
• One of the ideas is to give the players new mounts they can buy and allow these new mounts to be available for passengers.

New Continent
Northrend

• Northrend is Huge. It is larger than Outland by a couple of zones, and some of the zones in Northrend are bigger than the largest zone in Outland.
• This area will have two points of entry - Borean Tundra and Howling Fjord. To travel between these two zones, a "turtle ship" will be introduced: "a giant turtle with a deck mounted on top of its shell"
• Much like Shat is the 'home city' for Outlands, Dalaran is the 'home city' for this area.
• Dalaran will be a floating city, able to be accessed via land and flying mounts.It will be moved from Alterac, leaving "something cool" behind. NPCs will be left to explain the move - the KirinTor is at war with the Blue Dragonflight. It will be a neutral city, but with no trainers or auction houses. There will be portals, like Shat.
• Dalaran wil be in Nothern/Central Northrend, near the final zones.

New Areas (within Northrend)

• Azjol-Nerub

• Borean Tundra - It is the home of the Tuskarr. The Horde town is Warsong Fortress and Alliance will be Justice Keep. The Naga are up to no good by melting the icecaps. Not to forget the Taunka are lurking in this zone. This zone has both a Horde and Alliance entry point (along with a village). Caldarra, home of the Blue Dragonflight, is here and houses the 3-winged Nexus dungeon.
  
  • Alliance - brand new stronghold with a new leader; giant steam ship; stronghold gearing up to take on Arthas in the Icecrown Citadel;
  • Horde - enter into Warsong Fortress, under the command of Grom Hellscream's son - "huge and epic"

• Grizzly Hills - The Furbolgs live in the forest. The Venture Company is also cutting down the forest of Grizzly Hills. There also seems to be an ancient Dwarven City called Thor Modan. Most of the zone will be covered with trees instead of snow.

• Howling Fjord - It will hold the Daggercap Bay (a narrow canyon). Past the canyon you will find the town of Valgarde. The town is under constant invasions of evil Dragonflayers. The ancient Vrykul can be found in their instance Utgarde Keep.
  
  • Alliance - enter by boat through the Fjord walls, arrive in the middle of a big battle;
  • Horde - arrive in an area with brand new Forsaken architecture

• Icecrown Glacier

• Lake Wintergrasp
  
  • An outdoor region devoted entirely to PvP. Within this region siege engines will be available, as well as in the new battleground (name unreleased). There is speculation that siege engines will be available in all battlegrounds, but clarification is needed.
  • Siege engines will be able to destroy destructible buildings: the more you destroy, the more honor you get!
  • Siege engines are meant to be player controlled - emphasis on mobility and aiming!
  • New quest types will be available here: quests where you have to ride a mount with an NPC, holding attackers at bay; flying aircraft quests; flying mount quests where you have to lower ropes to evacuate NPCs; in these quests, mounts can hold multiple players!
  • The new battleground will be a 15-man area.
  • This PvP area will be PvP even on PvE servers.
  • Lake Wintergrasp will have daily quests, and there will probably be a buff that effects the entire continent, as well as rewards from all dungeons similar to the Spirit Shards players can currently get from the Auchindoun instances when their faction controls the area.

• Sholazar Basin - similar in appearance to Un'Goro, it has magical pylons that keep the Scourge at bay. It also has domes, similar to Netherstorm, that the titans conduct experiments within. Hemit Nesingwary has also crashed in this area!
• The Dragonblight - Where the dragons go to die. The home of Wyrmrest Temple, the ancient meeting place of the dragons. Within the temple is the Chamber of Aspects raid instance where players can fight the different Dragon Aspects. In the Dragonblight is also the Dragonshrines, each shrine dedicated to one of the Dragonflights.
• The Storm Peaks
• Zul'Drak - home of the Ice Trolls, contains Drak Theron Keep.

Death Knights

• In order to unlock this class, a player must have a character at level 55.
• They will start off in a floating necropolis in the EPL.
• Upon obtaining the Death Knight, it will not take the place of an existing character.
• Death Knights will start at a higher level than normal - level 55.
• The Lich King will guide you to become a Death Knight.
• You can create one per realm, per account.

----------Fight Style---------

• DKs will be a plate wearing tank/dps hybrid, able to use caster and melee abilities.
• They can use 2h swords or dual wield - no shields, only bladed weapons
• Meant ideally to tank against magic-damage-dealing bosses.
• Will have an "anti-magic shield" ability that diminishes the amount of magic damage taken.
• DKs will not have 'racial' abilities, but will keep those racials of their base race.
• They will have their own mount - a skeletal deathcharger.
• They will have their own talent trees, and will be able to have some sort of summoning abilities (undead)
• The Death Knight will have its own itemization as well as share the appropriate items.

• They have their own, unique energy system.
  
  • The new energy system for Death Knights is focused around the use of runes, rather than mana or energy.
  • The runes fall into three categories - blood (damage-oriented), frost (control-oriented), and unholy (utility and DOT mechanics).
  • The runes can be combined in different ways, then etched onto the Death Knight's weapon.
  • The energy of the runes is depleted when an ability is used, and not available until the cool down has expired.
  • Runic Power: builds up over the duration of a fight by using rune abilities, similar in mechanic to a warrior's rage; may get abilities similar in mechanics to a rogue's finishing moves
  • Can lessen global cooldowns, making it possible for the DK to fire off a rapid succession of spells.
  • Death Knights will be the first class to use diseases as a source of damage, with abilities that become strong depending on how many diseases are already applied to the target.

----------Possible new spells include---------

• Death Grip -- This is the Death Knight's "taunt" ability. It also pulls the target to the Death Knight, forcing them to attack the Death Knight for a short amount of time. Yes, I said pulls the target; Blizzard is going to allow players to move mobs in the expansion both with Death Grip, and other knockback/pull abilities. This works on players too.
• Army of the Dead - summons minions
• Unholy Embrace: Instant Cast. 5 min cooldown. Target is embraced by a silhouette of darkness for 6 seconds, corrupting any healing spells and effects cast upon or currently affecting the target to cause damage for 50% of their healing potential instead of restoring health. Any damage shields cast upon or currently affecting the target will also be instantly consumed, dealing 50% of their absorption potential in damage. Once afflicted with Unholy Embrace, the target cannot be afflicted with Unholy Embrace again for 1 minute.
• Death and Decay - Targeted, AoE Damage-over-time which pulses similar to the Paladin spell Consecration. Anyone affected by Death and Decay has a chance to be feared.
• Blood Boil: a damage-over-time ability, and after the end of the duration, it lights up two of your Blood runes.
• Death Coil - Depletes all Runic Power, dealing 600 damage to a non-Undead target, or healing 900 damage on a friendly target.
• Raise Fallen - can raise a fallen comrade or enemy as a ghoul; similar in utility and strength to hunter or warlock pet; when players have their toons raised in this fashion, they will have the option of controlling the ghoul
• Presences: similar to a paladin's auras, tied to the 3 rune types; self-buffs
• Anti-magic Shield: diminishes the amount of magic damage taken
• Chains of Ice -- Roots the target in place. When the spell fades, it places a snare on the target that reduces in potency as the duration runs out.
• Death Pact -- Sacrifices the raised ghouls to heal the Death Knight.
• Strangulate -- Depletes all Runic Power, dealing minor damage and silencing the target for up to 5 seconds.
• Summon Deathcharger -- Allows the Death Knight to summon a Deathcharger mount. This mount is acquired through quests, similar to the Paladin and Warlock land mounts.
• Raise Dead -- Raises a nearby corpse to fight for the Death Knight for 2 minutes. If used on a player corpse, the player has the option to play as the ghoul for the duration -- gaining access to the ghoul's abilities.

Raids and Dungeons

• Developpers think they didn't reward PvE enough in the Burning Crusade, and will try to change that in WotLK.
• Heroic dungeons weren't rewarding enough in BC, Wrath of the Lich King will change that and make player feel that Heroic instances have their own tier of loot instead of a few additions to the normal loot table. Expanding the Heroic Badge system will be a major step to achieve this.
• There will be no attunements or keys to obtain, and you won't be locked out of a 25-person instance if you decide to attempt the 10-person version, and vice-versa.
• 25-mans can be played as 10-mans, with different loot tables.
• Raids can be played on two levels of difficulties. Both options will be on separate cooldowns.
• Zero raid bosses have been designed at this point.
• In Wyrmrest Temple there's a raid instance similar to Onyxia's Lair where it's a small raid instance with a single encounter in the Chamber of Aspects. We plan to put a raid encounter in there and let you take part in that and initially we plan to go with one raid encounter, but if we want to expand the space and introduce other dragon flights we can do that through the Chamber of Aspects
• A raid encounter in the Nexus will let players free drakes and then fight on their back, allowing them to use their abilities. Bronze, Green, and Red drakes will be available and each one of them will have his own set of abilities. The boss fight is tuned around the abilities of the drakes and players will be able to pick any combination (e.g. 3 Green, 1 Bronze, and 4 Red). There's a boss fight that has lots of adds in it, and one of [the drakes] can apply this buff to a bunch of adds while another one can basically consume the buff and get health back from all of it and also assume a tanking role. So your tank is then healing himself based off of this debuff that another one is applying to everyone.
• The Arthas storyline will play out through the patches as well. So Arthas doesn't die in shipping Wrath of the Lich King. Arthas will die in a content patch.

• New Dungeons
  
  • Grizzlemaw (Furbolg dungeon)
  • New Caverns of Time instance (The new Caverns of Time instance will take you back to Warcraft 3 Stratholme. You will fight with Arthas (not against) to burn houses in Stratholme in an effort to “cleanse” the village from the Undead (or soon to be Undead). It has also been said we’ll see more what the Bronze Dragon flight is up to. The lore angle of this instance is that you will meet Arthas when he was still good yet here you are burning houses. Caverns of Time Stratholme will be a five-player level 80 instance. Mal'ganis will be the final boss of this instance.)
  • Utgarde Keep (5 player level 70 dungeon, inhabited by the Vrykul)
  • Dalaran instances
  • Drak Theron Keep: instance located in Zul Drak, home of the Ice Trolls
  • Naxxramas a sort of MC-like dungeon. The dungeon itself is a floating fortress so it can easily be moved to Northrend. Of course Naxxramas will be retuned to a 25 man dungeon along with level 80 content. They currently plan to include the same bosses. Some fights will remain the same while some, like the Four Horseman, will change quite a bit as it is adjusted to fit the 25 person raid model.
  • Nexus - will be a winged dungeon. One wing will be a 5-man level 70-71 dungeon called Ice Caverns. Also another level 80 dungeon will feature in Nexus. Another one of those wings will be a 25-man raid dungeon which will let you encounter Malygos. Nexus can be found in Borean Tundra. It will contain a lot of blue dragons.
  • Ulduar
  • (Outdoor) Azjol-Nerub (big underground land full of nerubians)
  • (Outdoor) Gjalerbron (Vrykul are working side-by-side with Liches)

PvP

• There will probably be two new Arenas in Wrath, one set in Dalaran, one in Orgrimmar Arena.

Classes
Druids

• Chance of being able to use roots indoors. Nothing certain yet, however.

Priests

• Discipline tree being looked at.

Shaman

• Chances on getting a crowd control talent.

Warlocks

• Doomguards and infernals will be getting buffed.
• New ability that enables them to place a demonic circle on the ground - they can then teleport to this circle (which will only be a short distance away) and will be able to summon demons faster within it.

Professions

• Will be 1900 new recipes across professions: 945 armor, 289 consumables, 139 weapons.
• Will be a daily cooldown on transmutes, etc. similar to raid.
• Will be new cooking recipes.
• Blacksmithing may be able to put Gem slots on items that didn't have them before.
• All professions will give players something powerful specific to them.

Enchanting

• Allowing enchanters sell their enchantments at the Auction House (at least some of their enchants).

Inscription (New!)

• Inscribers will create glyphs that allow players to modify their spells and abilities.
• Every player will get a new spell book page to which they can add six glyphs - currently, four major and two minor.
• Major glyphs will be effective in combat - adding damage over time or stun to a physical attack, for example - while minor glyphs will give convenient or cosmetic improvements, removing the need for some spell reagents. Like jewels and enchants, they'll be useful to every player; unlike enchants, they can be sold on the auction house, and indeed plans are afoot to allow enchanters to use auctions to sell their wares as well.
• They'll rely on the herbalist gathering profession.
• Glyphs can be sold at the AH.

New Items

• Fresh Glacier Water (9180 mana over 30 seconds)
• Crusty Flatbread (7800 health over 30 seconds)
• Frostweave - new Netherweave Cloth
• Cobalt - New metal

Known Factions

• Druids for the Ethical and Humane Treatment of Animals - opposed to Hemit Nesingwary (might be similar to Aldor/Scryer)
• Kirin Tor
• Oracles - similar to Murlocs
• Wolvar

Source
With the latest media coverage, we wanted to give you a listing of all the current links of available information. We'll do our best to add on to this list as further articles are released.

Curse Gaming
Demonstration impressions
Interview with Jeff and Tom

Ten Ton Hammer
World of Warcraft: An Exclusive In-Depth Look at the Death Knight
World of Warcraft: Dungeons, Daily Quests, and Raids in Wrath of the Lich King

IGN
Wrath of the Lich King Hands-On
Interview: Blizzard's J. Allen Brack
Interview: Blizzard's Jeffrey Kaplan

Gamespy
WoW: Wrath of the Lich King: A Long, Cold Day at Blizzard (PC)
World of Warcraft: Wrath of the Lich King (PC)
Pile-on: GameSpy Invades Northrend (PC)
WoW: Wrath of the Lich King: New movies!
Enter the Death Knight (PC)
World of Warcraft: Wrath of the Lich King: A Talk With J. Allen Brack (PC)
Wrath of the Lich King: Jeff Kaplan Interview (PC)
Wrath of the Lich King Raid and Dungeon Update (PC)

MMO Gamer
Behind the Blue Curtain: Discussing Wrath of the Lich King with Jeffrey “Tigole” Kaplan

WorldofWar.net
Breaking News - Blizzard's Wrath of the Lich King Presentation
Watch the new official WotLK Zones movie!
Wrath of the Lich King Presentation Summary
Death Knight - New Info, (including spells and abilities)
New screenshots
Tom Chilton Video Interview (Read Transcript)
Jeff Kaplan Video Interview (Read Transcript)
J.Allen Brack Video Interview (Read Transcript)
Wrath Presentation - All the Facts, None of the Fluff

Gamespot
Wrath of the Lich King Preview

1up.com
World of Warcraft: Wrath of the Lich King (PC)

Gamesradar.com
World of Warcraft: Wrath of the Lich King

Eurogamer MMO
World of Warcraft: Wrath of the Lich King Hands On

Source
You've seen the icy, menacing eyes, and gleaming metal and heard the ominous names of Arthas holding Frostmourne. Now we are calling all artists to bring these images to life with their vision of Arthas with Frostmourne!

Starting May 7, 2008, Epic Weapons and Blizzard Entertainment will be looking for the best original pieces of artwork that show the Lich King Arthas Menethil wielding his trusted runeblade Frostmourne and the Grand Prize Winner will receive a full sized 47" long replica of the Frostmourne sword courtesy of Epic Weapons and a guaranteed entry into the beta test of Wrath of the Lich King! Two runner up winners will also be selected for entry into the upcoming Wrath of the Lich King beta test.

We'd like to extend our thanks to Epic Weapons for the generous donation of the Frostmourne replica for this event, and for more information about Frostmourne, you can head over to http://www.epicweapons.com/

Visit the contest page to learn more about the contest!: http://www.blizzard.co.uk/frostmourne/

Source
We have decided to put the 2.4.2 PTR up for some additional testing. The realms should once again be available for play.

Source
We will be taking the 2.4.2 PTR down shortly and ending the 2.4.2 PTR phase.

Thank you to everyone who participated in this test phase. We hope to see you all again in future tests.