I went last night, possible spoilers ahead:
I loved it!! The movies (and books) keep getting better and better! The actors were all amazing, and I must admit, Gambon wasn't that bad in this movie. Luna was perfectly cast! She was exactly how I imagined her. Umbridge and Bellatrix were both great villans. The final battle was awesome and emotional.
My only complaint is the length. I think it should have been a bit longer to add some more stuff in. It jumped around a bit in the first half of the movie. I know they can't add everything for the sake of time, but 2 hours and 18 min is nothing compared to the movies we've been getting lately. I would have really liked to see Neville included in the prophecy. The way Harry heard the prophecy was weird. I would have also liked to see a longer talk between Harry and Dumbledore at the end.
Re-reading the book helped tremendously! I wouldn't have the above complaints if I hadn't done that. Seeing little details like the cats on Umbridge's wall and Hermionie's otter patronus was fun, something I wouldn't have noticed w/o re-reading before.
edit: I read on another site that David Yates is returning to direct HBP.
A little OT: I think the extreme HP fans are great! The extreme Pirates fans scare me, but not these guys. Someone brought beach balls like they do at baseball games (which I caught twice). And when the manager took them away, everyone started "casting" spells on him and calling him muggle, half blood, mud blood, etc. I also showed my friend this clip a couple days ago:
http://www.youtube.com/watch?v=Tx1XIm6q4r4. She was singing the song to my other friend and the guy in front of us turns around and yells "Potter Puppet Pals!!!" She looked terrified and had no clue what he was talking about. I nodded to him and said yes and he gave us all high fives.