Priests in MoP
Prayer of Healing can be used by Holy and Discipline once again. We realized that the goal of making Holy Nova an effective AE healing tool was problematic. It meant that we would have to change Holy Nova so thoroughly, that it was becoming a second Prayer of Healing. Remember: we aren’t even in beta yet, and we want to retain as much opportunity as possible to respond to player feedback throughout the rest of this process. Things will change for priests, and every other class, over the coming weeks.
There is some speculation that Discipline is intended only as a PvP spec or only as a tank-healing spec. Neither of those is our design intent. Both Holy and Discipline should be effective at group healing or single-target healing, and if we do our jobs right, both can have a role in PvP. The main difference between them is that Discipline relies more on absorption mechanics, such as Power Word: Shield, Power Word: Barrier, Divine Aegis and the new Spirit Shell. Holy priests should place more emphasis on heals over time and have more area healing mechanics (e.g. Circle of Healing, Holy Word: Sanctuary), but those are intended to offset the incredible benefit of absorbs and not to make Holy the only option for handling AE damage. We see both in use a lot in PvE in Cataclysm, and we intend for that model to continue.
More about Spell Resistance in MoP
First, the mechanic was implemented in a really confusing way. We could describe it all here, but it would take paragraphs, so instead we invite you to look it up on one of the fansites. The way a point of resistance leads to decreased damage is not an easy system for even experienced players to understand. We certainly could have redesigned the system, but to what end? Gearing for resistance sacrificed so many other stats that it was really only beneficial on those fights that the designers decided ahead of time would be "resistance fights," which generally meant getting a whole set of Nature (or Fire or Shadow, etc.) resistance gear. It felt more like an annoying speed bump to being able to progress to the next boss, rather than a fun challenge.
Secondly, the various resistance auras were passive things you'd just throw up, and pretty easy for any group larger than 5 to have. In designer parlance, we balanced around the assumption of their presence, rather than them feeling like awesome bonuses when you got to use, say, Fire Resist Aura. There isn't a ton of interesting gameplay there.
As we said in the blog, in some alternate universe, we could imagine a World of Warcraft itemization design where resistances are nearly as meaningful as stats like haste or crit. In that game there would be a lot of mobs that cast spells or use magical attacks, and stacking resistance might be an interesting trade off to stacking Stamina and armor. In the abstract, resistances could be cool. They aren't currently very cool in the actual World of Warcraft. We could spend a lot of design attention to make them cool -- and maybe someday we'll take that challenge on again -- but for Mists, we'd rather spend more attention on making sure the talent tree and spec revamps are as cool as they can possibly be.
Why there is a Conquest/Valor cap?
We do try to balance time investment with skill in the game. If there was no reward just for playing (time investment), then only the most skilled players would win Arenas or BGs or kill raid bosses and there would be no catch-up mechanism for the rest of us. This would demoralize and discourage players from participating, and the highly-skilled players would have no one to oppose in the BG or join in raiding.
Of course, if we overly reward time investment, then the value of skill gets diminished, which is very unsatisfying. The design we typically follow is to give the most skilled players the opportunity to accomplish things first, but let other players get there by eventually acquiring the gear and familiarity to accomplish the same (boss kill / acquisition of desirable piece of armor / achievement).
But we don’t like it when players run out of things to do. That's something that is always on our list of things to do to improve WoW. We’re not sure that removing caps is the right solution. We have discussed ideas like having diminish returns on Valor and Conquest, such that you always could earn more, but at some point the effort per reward becomes less and less desirable. Maybe under that model very dedicated players could continue to earn additional points, without creating a new standard for everyone. It’s tricky though, because we have to go with an option that doesn't quickly slide into something that feels mandatory.