Since there is only one released WoW expansion, and MMOs can last forever, you can expect WoW2 to be released in 2020 or shortly there after. In the mean time Blizzard won't release Diablo MMO because it is to similar to WoW and that prints money for Blizzard at the moment. A Starcraft MMO wouldn't be out of the possibility though (hell, it might get 10 million subscribers in S. Korea alone).










