From the self-reported results on the GradCafe's survey page from last year, the 10 schools I applied to all sent out decisions after the second week in February 2010. 8 of them had sent out some decisions in February while the remaining 2 sent out their decisions in March and later. More importantly (for me), none of the schools I chose sent out any rejections (at least based on the self reported results) until the middle of March, meaning that for the 4 weeks from mid-February to mid-March, all reported decisions from my schools were acceptances, while after that period, there were probably twice as many rejections as admits. This is not typical of grad schools, or even of Computer Science programs, since I myself got 3 rejections last February, but if this trend holds for my schools this year, then any contact I get before the end of February should be good. If I don't have any good news by mid-March, then the odds will definitely not be in my favor.
I've also been looking through the departmental calendars for the programs I applied to, since I remember last year people found calendars that had times reserved for things such as 'Admissions meeting'. Sure enough, one of my schools has dates between Jan 25 and Feb 21 marked 'Hold for interview' and has Feb 24 marked 'Faculty meeting to discuss candidates' and Feb 28 'Faculty-wide Admissions Meeting' - this was one of the schools that gave out decisions after February last year.
So for me it looks like it's on to February, maybe I'll get an interview invite before then, but I'm not expecting to hear anything until next month at the earliest.