For some reason I thought Catacylsm was a Jan release, realised after you pointed that out, that it was out in December.
Regardless, I still say Q1 2012 for Diablo3
And to those saying the longer the release takes the less money they're going to make, I really don't think so. Diablo 3 is one of those games that any true Diablo fan will buy regardless of how long it took. I sure as hell know I'm not in any rush, 2011 is supplying an abundance of amazing video games that are going to keep me busy for quite some time.