Microsoft announced the release date to Alan Wake at their X10 event, what was thought to be for both the Xbox 360 and the PC is unfortunately not the case. The company has confirmed it is now a 360 exclusive.
"Some games are more suited for the intimacy of the PC, and others are best played from the couch in front of a larger TV screen. We ultimately realised that the most compelling way to experience Alan Wake was on the Xbox 360 platform, so we focused on making it an Xbox 360 exclusive. Both Microsoft and Remedy have long histories in PC game development. This decision was about matching this specific game to the right platform."