(I posted this in the MMORPG.com article of what could be next for WoW expansion wise. But figured it be good for its own thread too).
I'd be 100% good with 3 types of expansions, maybe 4
An overhaul (again) of azeroth. We have spent longer in "Cataclysm" zones than vanilla WoW zones. This would probably be a more laid back kinda expansion of time of rebuilding and what not. Maybe gearing up to The Old Gods...so kinda an in-between expansion getting ready for a huge enemy. There would be a lot of signs and influence of The Old Gods affecting Azeroth.
The Old Gods, though I'd rather have it be built up in an in-between expansion...but I'd be completely fine if we just went straight there. There are hints that is what is happening with a certain artifact saying there is a bigger enemy to worry about and to stop "playing" with the legion and get it over quickly.
I guess a lot of people want to see South Shore as an expansion, which could be possible and WOULD be a laid back expansion and a lot of gearing up to The Old Gods, maybe even more than the 1st expansion (the overhaul of Azeroth zones). I think this one and the overhaul of azeroth could be equally likely. I don't think blizzard is going to jump right to The Old Gods, with maybe the certain artifact suggesting otherwise
Or The Lich King Returns Again...seems meh though to fight a 2nd lich king. And I doubt it'll be the next expansion, but with the DK story, there is signs that something is happening with the new lich king and not all is good. Though this one is pretty unlikely compared to the above three. Never know though. But I'd be kinda okay fighting the 2nd lich king, but there isn't much gearing up to that except for the DK story, no signs of scourge being bad again...with an exception that maybe the Old Gods could be influencing the new lich king (again).