I've never been a fan of scary games…I hated Condemned and I couldn't play FEAR at night time, so chances are that I won't enjoy Alan Wake.
When it comes to scary games, they fall into two categories:
a) games that take themselves way too seriously and try so hard to scare you that the whole tactic backfires and the game just comes off as corny.
or
b) games like FEAR, where the gameplay is great, but the atmosphere is so real, so intense, and so terrifying that it creates a legit horrifying experience.
I get the feeling that Alan Wake falls into the latter category.
Here's the trailer from E3: