It was speculated before the Diablo III announcement at WWI Paris that the crew at Blizzard was developing an new MMO.  There was speculation late last year thanks to job postings on Blizzard's end.



In the video above Rob Pardo VP at Blizzard confirms they are working on another title that happens to be a next generation MMO.  He notes "there is still one unknown project..." and those job postings had nothing to do with Diablo III.

Let the rumors continue on.  World of Starcraft anyone?  That seems more likely that a new totally new franchise as a MMO.  You already have so many Starcraft fans so why not take advantage of that audience and the World of Warcraft audience that may enjoy it as well.  Since the success of Warcraft II, around 1995 they haven't stepped foot out of the Diablo/Starcraft/Warcraft worlds.  Is it time to start on a new franchise?

Maybe they will actually release one of their three current games before announcing the fourth. 

Thanks to Shacknews for the scoop.