I just saw the movie today (finally). It was quite good, but definately not my favorite. I've read through all of the previous comments, and agree with almost all that's been said. In summary: it should have been fleshed out more - there should have been more subplots, WAY more emphasis on some of the characters (such as Sirius, Bagman, Crouch, Malfoy, and the FREAKING HOUSE ELVES). I'd be more than happy to watch a 3 hour Potter movie. I just fear that come around the fifth or sixth movie, they're going to have some blatant plot discrepancies due to mistakes that were made early on in the series.
As for the individual acting, I think the new Dumbledore (Michael Gambon) has fit the role's shoes far better this time around than Azkaban. Still, no one will ever replace Richard Harris, may he rest in peace.
As for Harry, I'm finding him quite disappointing. Acting is definately not his strongpoint. I also feel like the script is partly to blame, like all his dialogue gets cut and he's just dumbed down. In the books he's so much sharper, catches on to things way quicker and asks much more questions, instead of that stupid blank stare that's meant to make him look cute that he does in the movies. ACTING IS NOT JUST STARING INTO SPACE WITH MUSIC PLAYING.
After watching the movie and seeing the final scene (which did, by the way, seriously rock) I thought to myself "There's no way this kid could defeat the greatest wizard of all time the way he's bumbled his way through this movie." His acting, dialogue, and overall screen presence just didn't cut it for me. Harry needs to be FAR more magically talented, fierce, intelligent, and tenacious in the future movies if it's going to work.