One of the most often asked and debated questions on WoW Insider lately has been:"What is after Ulduar and patch 3.1?" While no one can know for sure, we do have some evidence out there that can help us at least look smart about it.
Back in October 2008, Kaplan said in an interview with Curse that Patch 3.2 will contain a new raid instance that hasn't been announced yet. There's some question as to what exactly he was talking about. We also know from the article that Patch 3.3 will contain the Icecrown Citadel, so we know the 3.2 dungeon won't be that.
There is also the possibility that Kaplan didn't mean a new raid instance in Patch 3.2, but a new battleground. Many people think this is the case. Zarhym confirmed that there will indeed be a new battleground sometime in the future, and signs point this happening in patch 3.2.