The movie also just looks gorgeous. In the repeated scenes that have Draco working on the Vanishing Chest, he walks past a bird cage that cuts up the shot, giving the scene a nice gothic air, and is progressively empty as Draco's experiments kill some of the birds. The ink swirls that condense into memories are similarly dark and lovely. The whole movie looks as it was filmed during a period of unrelentingly bad weather, which only serves to make a final sundrenched scene, as Harry, Ron, and Hermione prepare to leave Hogwarts, more emotional and lovely than the leaden dialogue (lots of telling, no showing) in that particular moment would otherwise allow. It's not, you know, a stunningly original cinematic tale or anything, but that feels less like the point. I just want to go to the movies to feel a bit of the atmosphere of the books again, and this movie accomplishes that handily.
Abridgement
I went to see Harry Potter and the Half-Blood Prince last night, and I enjoyed it a lot, in part because I thought the filmmakers diverted from the novel in ways that were both cinematically interesting and advanced the plot. In particular, I thought the attack on the Burrow was beautifully staged, emphasizing the isolation of the house, Ginny's feelings for Harry, and getting together Tonks and Lupin in a way that eliminated a lot of the moping that dominated Tonks' character in the novel. But there was one omission that bothered me, and I couldn't think of what it was until this morning: we don't get to see Snape teaching a potions class. As someone who believes it really is not possible to have too much Alan Rickman, ever, it's a disappointment.