I haven't seen it because I have heard pretty bad reviews about it. Also Edward Norton really didn't want to be in the movie after reading the script and tried getting out of it, but he was bound in a contract so he couldn't.
I saw it over the weekend, and I really liked it. The previews did give an awful lot away though... but they're also what drew me into wanting to see the movie. I love Seth Green's character - I'd say more, but I don't want to give anything away. I'm putting the DVD on my wishlist when it's available.