Above all else, I really liked the way this tied the whole series together. I've got a lot of respect for the fact that most of the key hints were in the previous books; this mainly tied them together, in a way that was mostly very natural, even obvious in hindsight. This was especially the case for "The Prince's Tale", which basically just said that everything we'd ever been told about Snape was correct: he really was one of the good guys, and really was working for Dumbledore all along. Simply by adding one small, apparently unrelated detail -- the fact that Dumbledore's wasted hand was the sign of a fatal curse -- Snape's actions in book 6 made considerably more sense.
It'll be interesting to see how they make this one into a movie. Not only is this book just as long as the rest, it's denser than many of them. Heck, the special-effects extravaganzas alone will take up a good chunk of a two-hour movie: I'm sure that they will milk scenes like the escape from Greengott's, the fire demons in the Room of Lost Things, and the final Battle of Hogwart's for all they're worth. I suspect they'll squeeze it all in by entirely dropping the B-plot (the history of the Dumbledores) as they've done in some previous movies, which is a real pity, since it is where the depth of the book lies.
On the flip side, it was fascinating to see how much this novel was influenced by the movies. A bunch of physical descriptions snuck in, that I'm fairly sure came from the movie interpretations in the first place. (That is, I didn't remember the descriptions from the previous books, but they match the movie renditions precisely.) And I think Rowling's style has gotten a bit more cinematic, with a better sense of what *looks* dramatic working its way into the book. The final showdown, with Harry and Voldemort circling each other, wands at the ready, should be absolutely delicious when it gets filmed.
I'm not sure whether I'm imagining it, but I was very struck by the number of scenes that seemed to echo other cultural artifacts -- literature and movies. There was "the Excalibur scene" in the frigid lake; the "Aslan scene" of Harry voluntarily going to his death, and Voldemort's misunderstanding of how a willing sacrifice works; the "2001" scene in King's Cross; and so on. I'm not sure that any of them were intentional -- they're all very primal scenes, and none were really direct ripoffs (except maybe the Aslan one) -- but I can't remember the last time a book had so *many* of them.
The Masonry question that I raised earlier falls into this category. I'm still very struck by the fact that the sign of the Deathly Hallows is described so much like the eye in the pyramid, is used as a sort of shibboleth, and is associated so specifically with the subject of death and resurrection -- very Masonic topics. But again, it's just an echo of Masonry, subtle enough that I *could* be entirely imagining it.
Anyway -- overall, a very good book. The last third, in particular, was the dramatic high point of the series (as it should be). I have to say, though, for my money, the climax of the story -- the moment that deserves the dramatic slo-mo in the movie version -- isn't Harry at all: it's the moment that Neville pulls the sword from the hat and lops off the snake's head. To those of us who have been rooting for Neville throughout the series, it was damned satisfying...