Just saw a link on FARK that went to a press review of this movie. They really tore it apart, saying that it completely destroyed the story and stripped out all the humor and character development and replaced them with slapstick physical comedy and special effects. Anyone who is a fan of the book will be supremely disappointed, and anyone who wants to see a good movie that makes any kind of sense will be as well. Hopefully the reviewer is wrong, but he went into quite a bit of detail on what is and isn't in the movie. If you don't mind a few spoilers, check the review out here:
www.planetmagrathea.com/shortreview.html