Go ahead a strike the possibility of a World of Warcraft 2 off your list of possible next-gen Blizzard MMOs because it's officially not happening. In an interview with Wired, Blizzard's recently talkative Mike Morhaime flat out said that their next MMO project isn't a sequel to their first. Of course, he wouldn't divulge exactly what it was either or this would be an entirely different sort of news post.
With this news, the odds for a StarCraft or Diablo MMO go up, but so do the odds for an entirely new IP as well. We're sure the guessing game will continue for quite some time before Blizzard tips their hand to everyone. At least the mystery will offer all of us something to do for the next few years while we wait for other unannounced super-secret games to be revealed in the meantime.