Blizzplanet has just updated a small news post about the MoP launch event, where Chris Metzen took questions from fans about the game.
He confirmed that Turalyon and Alleria Windrunner will return in the next expansion of World of Warcraft.
The implications to this are huge. It probably means we will deal with the Burning Legion one way or another in the next expansion, which supports the theory sparked by the Orgrimmar raid. It also means lots and lots of Sin'dorei / Quel'dorei lore due to the return of one of the Windrunner sisters, so blood elves and forsaken - rejoice!
Most of all, it means that the Alliance will get back the hero from the Second War who at this point is probably the greatest living hero of the Alliance and the best card they have in their deck.
Anyway. FOR LOTHAR!!!
The video of the launch event is available from Machinima's YouTube channel, here.
Chris Metzen answers my tweet at 2:45:30, and ultimately his answer is this:
'[...] however [...] in terms of what's coming next, you're gonna need their help.'
'Next' could either be interpreted literally, the next expansion - or it could be interpreted as the coming few expansions. I think it's the first one.