There are a lot of things missing in the new PTR 5.2 patch and I'm pretty sure we will talk about the Isle of the Thunder King again in the new future.
Let's see now what do we know about this new area:

• Isle of the Thunder King is the new daily quest area. There are about 7 random daily quests each day.
• You'll have to deal with both Zandalari and Mogu.
• The Throne of Thunder is located in here as well.
• The entire are is a no-fly zone.
• Currently you can access the area by using the portals located near Shado-Pan Garrison in Townlong Steppes.
• Most of the things from horde and alliance bases are still placeholders.
• The horde and alliance bases are protected by some beacons and by Silvermoon Spellbreakers and Sunreaver Constructs.
• The area is filled with quest mobs and you can also find some rare spawns.

We will come back to this place when more details are available and when the placeholders are gone. Until then, enjoy the screenshots below.