Last night, Famitsu magazine confirmed that Heavy Rain would be launching in Japan on February 8th.  This gave credence to a February release date that was being reported by several online retailers. 

Unfortunately, though, it doesn't seem that a Western release has been established yet.  We contacted Sony earlier today in regards to the news, who replied "We haven't set a release date for Heavy Rain yet I'm afraid".

Still, considering the game was originally slated for a 2009 release, we wouldn't be surprised to see it pop up around that time frame.  The game has be content complete for months now, with Quantic Dream ironing out bugs for the last half a year or so.