After reading the book, I already knew from the trailer's that the movie was not going to be the same. Zombie's instead of vampires, NYC instead of So Cal, etc. Anyways, I enjoyed the movie to a point, and whole heartedly agree with Stang that it could have been so much better. It really was a disappointment from that view point.
The one thing I do wish Hollywood would do, is actually have some quality contrl people watch the damn movies a few times to pick up mistakes or things that just plain don't make sense. That in itself was enough to rate the movie low.
Again, reiterating what Stang said, It could have been so much better.