when is the next wow expansion after cata coming out

Answer 1

I would've thought they'd bring it out in the next 2-3 years depending on the release date of the deathwing raid.

I would've thought perhaps 2014 around December would be a safe bet,

As for what the expansion would be in my personal opinion it is probably the Emerald Dream which would most probably include a whole new land (Kind of like TBC) because of the numerous hints left in the game that this would happen e.g:

Cataclysm - You open a portal at Hyjal that leads into the dream, Malfurion Stormrage (Spelling may be inaccurate) returned from the dream and I'm pretty sure someone from the Bronzebeard clan of dwarves did too.