Not a bad movie, better than some of the others. Sure they dropped oodles, and true they could've cut differently, but I'm glad they finally got a good weasley twins spot in the film. They also dropped at least one point that should be in there (plays into the next films). But overall, better than the last one. It's not too bad, so long as you leave enough time between a reading of the book and the movie, also think of the movies as more of the book: Re-imagined.
I'd say it will do well. It's great if you have kiddies, and still decent if you don't.