A new rumor has surfaced today surrounding the release dates of StarCraft II and Diablo III. According to an "anonymous source" within Blizzard, Diablo III will be released prior to StarCraft II despite it being announced after.
Naturally, as with all rumors, take this statement with a grain of salt. For all we know, StarCraft II may come out months ahead of Diablo III. Until Blizzard makes an official statement, speculate all you want!
Source
(Starcraft 2) is still being worked on, but only by a minuscule amount of people compared to what (Blizzard) put on the Diablo 3 team.
Naturally, as with all rumors, take this statement with a grain of salt. For all we know, StarCraft II may come out months ahead of Diablo III. Until Blizzard makes an official statement, speculate all you want!
Source