I saw it last night. Really enjoyed it, although I haven't read the book since it first came out so I can't really remember how much is missing.
One thing which didn't really seem to fit though, for me, was when Harry used Snape's curse on Draco. Two students viciously fighting with magic, one ending the fight by using a dark curse on the other, and yet there seemed to be no consequences, even though Snape must have recognised the curse. Harry simply walked off. Can't remember the original version from the book, but I doubt Harry simply buggered off afterworRAB without consequence.