I read the book. It's one of those stories that's designed to start off with you not knowing what's going on, so the entire story - the people, the world, everything - unfolds in front of your eyes and becomes clearer and clearer as it goes on. It's a pretty powerful tale, particularly as it's coming from the POV of a 9 year old boy. Having read the book, I... don't think it can possibly work as well as a movie. Oh, I'm sure it's a very good movie, but they'll have had to adapt the narrative style to make it work and I imagine it'll be much more character-based than discovery-based.
I guess if you've seen a preview for the movie, you already know more about what's going on than I did before finishing the book, but I still say you should read the book before seeing the movie, because I don't think you'll be able to get the same sense of discovery AT ALL from the book if you already know everything that's going to happen.
