Blizzard... how my blood boils at the very sound of that name.... everyone is guessing october of 2009 or alteast that WAS the guess, but I stopped keeping tabs on it after focusing on Left4dead
Ah, Blizzard. Yes they are notorious for delaying games. But I'd rather them delay the game a bunch of times and release a polished game, then push it out fast and have to deal with a buggy game that requires a ton of patches to make playable.
I believe I read recently that Blizzard has confirmed that to be true.
As far as a release date goes, this far in advance, it'd be nothing more than a goal they hope to meet. Release dates in software development are fairly unpredictable as it is, but considering Blizzard's track record, it's exponentially moreso.