So, wondering what scenes need to be kept, and which will be let go, based on the scenes we've, um seen:
1. Malfoy performs Petrificus Totalis on Harry on the train.
2. So, I can assume that Tonks will find him, in her depressed state.
3. Met by Snape, who notes her patronus.
4. Narcissa is cast, so her and Bellatrix's meeting with Snape to perform the Unbreakable Vow will have to be shown.
5. Perhaps a scene with Draco and Voldemort hinting at what "the job" is, without revealing too much.
6. The "traveling wardrobe," for lack of a better term, was first noted in HP&TOOTP book, but not disclosed in the movie. Will Nocturn Alley scene with Draco be shown? I mean, the bad guys have to get to Hogwarts somehow, if not by the book's means.
7. Quidditch back, in order to advance the XXX-YYY romances. Haven't seen whether McLaggen role has been filled, so I'm not sure if a lot of Quidditch will be shown. Felix, Ron, and Harry will play a role in the "first" match. McLaggen and Harry in the second (and possibly Draco in a non-playing role), while Ginny plays a big role in the third, probably not shown, match, while Harry is off doing something else after a bad decision to use Sectumsempra on someone.
8. I need more from Snape. Apparently, Rickman was told of the major secret that Snape told Dumbledore, in order a) to get him to play the role (can't see anyone else in it), and b) to put some motivation in his acting. I want to see that hatred in his face, because of what he has to do and not because he wants to, and even though he knows it doesn't really matter in the extremely large picture, etc. (trying not to give too much away for the extreme unlikelihood of viewers here who have not read the books).
9. All of the memories have to be shown. I can't see one that can be cut. (I'd like to see Angela Lansbury as Hepzubah (sp) Smith.) It's possible that instead of six separate meetings with Dumbledore and the Pensieve, one, maybe two max will be done.
10. Cut a little out of the cave scene.
11. Not sure how much of Kreacher will be cut, since his major role in HP&TOOTP was cut. (We know now how Dumbledore found out about the cave, though, even if it is never explicitly disclosed in the books.)
12. I hope that Harry uses the RoR to hide his book, and that a certain item is subtly shown. Otherwise, "DH" will have a huge plot hole.
13. Nobody filling the role of Fenrir Greyback (possibly CG'd), so that whole plot could be nixed.
14. Fleur Delacour doesn't seem to be cast for this movie. Another plot hole for "DH" going out the window? That means no Christmas at the Burrow, no Bill getting injured, no wedding in "DH"?
15. Could skip the whole funeral scene, opting for a passing shot.
16. No mention of Scrimgeour on IMDB. I would find it amusing if Hugh Grant (recurring role from "Love, Actually") were to play the PM in the opening scene (if the book were to be followed closely). I can see that whole scene being cut, though, but it would be a nice way to show that at least the people at the top of Muggle government know about the Wizarding World (even if their memories are erased after they leave office).
17. Nice that the Ginny thing was being subtly hinted at in TOOTP movie, though there was no hint of her having other relationships, as the book noted. I'm sure there will be a few less subtle moments in "HBP."
18. There are so many moments in the book where the three major characters are not together, that it will be a different feeling movie from the others. A lot more Harry-Hermione scenes, which should frustrate that lot of "shippers." The ward scene after Ron's "injury" will have to be there. And a not-in-book Hermy-Ron kiss (finally) will not be unwelcome. No need to wait until "DH" for that.
I'd like at least three hours and 45 minutes, please. At least. I'd like "DH" to be a "Kill Bill Volumes I and II"-style event. Split at the point when Ron rejoins Harry and Hermione.