I wont buy this game for the same reason I didn't buy their last series: I'm a scared little skirt when it comes to games. Horror movies? Love them. Horror fiction? Awesome. Horror games? I literally have to have my wife sitting beside me watching me play in order to do it.
The only exception seems to be L4D, which I expect is a combination of many factors such as the bite-sized play times, the rampant humor, and the fact that I'm playing with other people.
Oh, and Doom 3. I just couldn't take it seriously. Wolfenstein 3D gives me more chills than constantly spawning some daemon from hell every time I turn my back 