Despite the delay of StarCraft II into 2010, Blizzard says the release of Diablo III will not be affected by the shift.”I will confirm that the move of StarCraft into 2010 does not affect the release schedules of any of our other games,” said Blizzard president Mike Morhaime.

When asked whether that means Diablo III and StarCraft II could both be released in 2010, as Blizzard had previously said to expect a major Blizzard release each year, Morhaime’s response implied that possibility.”We haven’t announced any release dates on any future title. And I’ll also reiterate that the [move of] StarCraft into next year does not impact the schedule,” said Morhaime, who then, with a slight laugh, added: “And so it would be correct to conclude that you could expect two releases of Blizzard next year. But I will not make any conclusion as to what those titles will be.”

source: shacknews

I’m willing to bet a million bucks that Diablo 3′s gonna be delayed to 2011 if they’re releasing Starcraft 2 Q3 to Q4 of 2010. It’s gonna affect sales of D3 and SC2 if they release two powerhouse games at the same time.