Unfortunately, some of my favorite parts got the ax:
- Most of the events in Dumbledore's office at the end of the story. I was particularly looking forward to seeing a particular pair of lines: "This pain is part of being human—" "Then I don't want to be human!" That moment, to me, makes the book, and would've made the movie.
- Hermione being hurt in the DoM, and Harry's reaction to it. It's sorta-kinda implied by the way the DoM is filmed, but it's much less clear.
- For that matter, most of the nifty random stuff in the DoM. In particular, there was no time room, so the movie canon will probably have a plot hole involving Time Turners that the books won't.
- The original Dumbledore/Voldemort fight. In the book, it's very much a battle of wits, with each wizard turning the other's attacks back against him; in the movie it's more a battle of wills, and I think both characters suffer for it.
- The full train wreck of Harry/Cho.
- The visit to St. Mungo's (although they did find a way to grow Neville's character).
- Kreacher's betrayal. Kreacher himself was present, so I assume this ended up on the cutting room floor.
- Harry's career counseling.
- A lot of great lines throughout. I only recognized a few of the best ones—the "emotional range of a teaspoon" line, the "come quietly" line (though not the rest of that incredibly awesome section), the "he's got style" line (in someone else's mouth), and the "it was foolish to come"/"by which time I will be gone" pair. But Dumbledore and Voldemort are such different characters in the movies that their lines seemed out of place.
They also continued fucking with the whole concept of how wizards fight. I'll be seriously irked if Harry can't turn into a flying wraith thingy by the end of movie-DH like all the minor characters can.
On the other hand, they did keep this movie efficient. The thing that bothered me the most about GOF was not that they cut so much; it's that they expanded the three Triwizard tasks so much when they could have used the time for omitted plot points. But there wasn't any of that in OOTP, so the cuts don't hurt as much.
Also, I loved how they dealt with the fact that so much of the plot is in public opinion and newspaper headlines. It's like a dynamic, updated version of the old spinning newspaper cliché.
Luna is simply fantastic; the promotional pictures, which always have her looking focused, don't do her portrayal justice. Oddly enough, she wasn't how I imagined her—I always imagined she'd have a more matter-of-fact tone when talking about all the stuff she believes in—but Evanna Lynch's portrayal is probably more true to the book's description than what I was thinking. They really found the perfect girl for the role.
Some particular scenes they included or added (IMHO, at the request of Rowling) might hint at events in book-DH:
- They showed Ginny's overpowered magic. I suspect this'll be integral to DH. Dammit.
- They didn't show catgirl!Hermione during the Occlumency lessons, but they did prominently include the hug from the beginning of the movie. H/Hr fans, time for a happy dance.
- Even though they didn't include his betrayal, they did have Kreacher.
- Tonks and Lupin were both around, though neither of them was named (that I remember). Tonks's Metamorphagus ability was shown, so I think that'll come up in DH as well.