Overall, I'm very pleased with the book.
Snape definitely is tragic. I've actually been re-reading the last 150 pages every night since Sunday. I was thinking that had Snape been a woman currently living in the US, popular culture would have cast her as a pathetic spinster who isn't able to move on.
The epilogue is unsatisfying in that it doesn't tell you what any of the trio that we've grown to care about is DOING 19 years later. We learn that Neville's a professor at Hogwarts and that everyone has a ton of kids, every one of whom is named for someone deceased. I don't think Rowling is likely to write something as epic as Harry Potter, but I can foresee shorter books in a future series (like Sweet Valley High -- hee hee). With Voldemort kaput, there's nothing to really left to drive the story unless something happens with a Death Eater offspring. So, I can see an "Adventures of ...." type of thing if anything, but nothing as elaborate as what we've seen so far.
The movie for Book 7 will probably be PG-13, no? Lots of implied swearing, and of course, the Mrs. Weasley exclamation. I was disappointed that Neville did not exact revenge on Belletrix and that it was Mrs. Weasley who killed Belletrix instead. I had this image in my head of a censored version of the movie being shown on TV in 2 years. You know how instead of saying the B word on broadcast TV, they dub in "witch"? Is it not hilarious, in the context of
Harry Potter, for Mollie Weasley to be yelling at Belletrix LeStrange, "NOT MY DAUGHTER YOU
WITCH!" (P. 736).
I went into the book thinking about Judeo Christian themes, ie, Harry as Jesus, Voldemort as Satan, Snape as Judas (as much as I didn't want to believe it), Dumbledore as God, Hermione as Mary Magdelene (sp?), Ravenclaws and Griffandors as Harry's disciples (even with Dean Thomas at one point disbelieving Harry's assertion that Voldemort was back). Resurrection of Harry, etc. The analogy isn't clean, though, and I felt like Voldemort was more Pontius Pilate than Satan.
There was obvious imagery in there reflecting low periods of world history, such as the persecution of Jews and internment of Japanese Americans during WWII.
The theme that most intrigues me, however, is that of love. Dumbledore says that Voldemort is devoid of love and repeatedly tells Harry throughout the series that it was Lily Potter's love for the child that saved him as a baby. As book 7 progresses, we see instances of several types of love: a mother's love for a child (Mollie Weasley for her children; Narcissa Malfoy for Draco; Kendra Dumbledore for Ariana D.); romantic/idealized love for a partner (Snape for Lily; Lupin for Tonks); platonic love (Harry for his friends, and vice versa); some lust (Ron and Hermione; Harry and Ginny); and maybe a crush-like/infatuation (earlier in the series, Harry for Sirius - I mean, Harry seemed to idolize him; Harry for Dumbledore? idolization again; perhaps any younger students towards Harry). Would a house elf's relationship with his master be a sort of agape love? Maybe that's stretching it a little....
Anyway, those are some of my thoughts on the book/series!
Oh wait, my final thought was the theme of orphans and abandonment. I had read in a Washington Post article that Rowling has obviously been compared with Tolkein and CS Lewis, but perhaps the writer she shares the most in common with is Dickens, who wrote for the masses, had colorful names for his characters, and whose protagonists have tended to be loners and orphans. I haven't read any Dickens lately, so I'm not sure what to make of that.