Mists of Pandaria
Blizzard just trademarked a very interesting "Mists of Pandaria".

Source: http://www.mmo-champion.com/content/...ts-of-Pandaria

Of course, this is all speculation still at this point, but this is true news nonetheless and since it clearly shows that it will be a game, it's quite likely that it's also the next expansion for WoW.

If it is, I guess I'll still have to return to WoW at some point. I just adore Pandaren.

LET THE SPECULATION BEGIN!

EDIT: Also, update on MMO-Champion:

Update - For the record, the international codes 009 and 041 only seems to appear on Blizzard's online games trademarks. This isn't a book or anything like that. It appears incredibly likely based on previous trademarks obtained by Blizzard that this is the next expansion.