During the CES Microsoft keynote Robbie Bach confirmed that the upcoming Alan Wake will receive additional download content post-launch. Alan wake is expected to hit sometime this Spring on Xbox 360.
Robbie Bach said, "Imagine the TV show Lost, as written by Stephen King, and filmed by David Lynch, and you have Alan Wake. Story driven like a TV series, Alan Wake will be told in episodes, with even more episodes available on Xbox Live after it's launch this year."