So, my thoughts on it is its going to be a sci-fi type game, and i think its going to be announced at blizzcon, My reasoning?
Star Wars, The Old Republic. this game is looking brilliant and i cant wait for it, Everything is voiced, You can change what happens to you in the future depending on choices you make in the beginning instead of the same repetitive quests like wow, space combat and an overall better gameplay in its own aspects.
but with blizzard seeing everything they are doing to improve on the mmo experience in general, blizzard is going to take all of that and try to squash it to the ground so they dont have to fight with anyone still and can take the entire market for themselves, so i believe to get rid of some of the hype for swtor we will see they're new mmo.
TLDR: Swtor is looking good so blizzard will try to squash it with announcing the new mmo come blizzcon
Edit: i want your guys thoughts on the matter or your opinion, but please dont make this a wow > swtor thing or anything along those lines please