I'm not sure if it can move as much as some predict, Alan Wake doesn't look like blockbuster title which UC2 was. Survival Horror isn't really everyone's cup of tea. I for example would shit myself playing that game, so that is the reason why I wouldn't get it.
I believe it can make slight bump, couple of thousands, but nothing huge. I personally can't see any game moving much of Xbox's hardware with the exception for Halo Reach. Same as PS3 will probably see some love from GoW and GT. Other titles doesn't feel like hardware moves.
MY HYPE LIST: 1) Gran Turismo 5; 2) Civilization V; 3) Starcraft II; 4) The Last Guardian; 5) Metal Gear Solid: Rising