So apparently there's a new Panda race and Monk class coming along to WoW.  I don't why Panda's but I'm sure Blizzard will still sell copies. The new WoW exp will also have:

    Pandaren, a new playable race
    Monk, a new class
    An increased level cap of 90
    Several new zones on a new continent
    PvE Scenarios
    New Challenge modes for dungeons
    A new talent system
    Pet battling system

World of Warcraft: Mists of Pandaria Preview Trailer

For a more detailed info/pics:
http://us.battle.net/blizzcon/en/blog/3768753/World_of_Warcraft_Preview_Panel_Mists_of_Pandaria-10_21_2011

As will most WoW Fans. I am certainly not one of those.