I disagree with Dan Drezner and Ross Douthat; I thought it was fine. Spoilers follow.
Winding up a series like this one is a massive challenge to an author. I thought Rowling rose to the occasion. I was especially impressed that she was still introducing major plot elements (Dumbledore’s family history, the Deathly Hallows) halfway through the last book, which might have been expected to be mostly the tying up of loose ends.
Conceded that the plot creaks at various points. Why doesn’t McGonagall, in her tenure as acting headmistress, interrogate Dumbledore’s portrait? Why don’t Harry, Ron, and Hermione buy or Summon some non-perishable food — nuts, for example — and feed themselves by increasing its quantity?
(I lost my trust that Rowling was in full control of the plot way back in Book 4, when the brilliant and inspired “Mad-eye” turned out to be someone who had spent his adolescence as a Death Eater and his subsequent years either in prison or isolated at home. There’s just no way that Barty Crouch Jr. has the self-possession that he displays as “Mad-eye,” or the wit. When McGonagall asks him what he’s doing in bouncing Draco Malfoy-as-ferret off the stone floor, he answers simply, “Teaching.” Where could Barty Jr. have gotten that? Or again, when Harry tells the Minister that he won’t cooperate as long as Stan Shunpike is in Azkaban, why doesn’t the Minister offer to trade Shunpike’s liberty for Harry’s help? And why doesn’t Dumbledore, while the Philosopher’s Stone is still in existence, make enough gold to be able to buy the loyalty of dubious allies like Mundungus and Slughorn in the battle he knows is coming?)
And conceded that the loss of the school-story element deprives the last book of a valuable structural element, though it’s also part of the growing-up of the three central characters.
Dan thinks the Deathly Hallows are a mere distraction. To, me, they echo the point made in the first book: that even in a world of magic, an obsession with magical objects, especially those that promise to overcome death, is a temptation to be resisted.
The theme of the series is, simply, death, and the importance of accepting it and not fearing it. In Book One, Dumbledore displays his wisdom by destroying the Philosopher’s Stone. In Book Seven, Dumbledore succumbs to folly by trying to use the Stone of Resurrection, and Harry at last surpasses him in wisdom by simply letting it drop.
Yes, there are some missed opportunities for character development. Or perhaps those are authorial choices. Dudley Dursley improves; Malfoy doesn’t. Slughorn fights, but he doesn’t rally the Slytherins. That’s life.
Dumbledore is perhaps Rowling’s greatest accomplishment: a great sorcerer and a wise teacher, of course, but enlivened by a sense of humor: “Nitwit. Blubber. Oddment. Tweak.” “Warm socks.” Still, as seen in Books 1-6, he remains a mere Merlin or Gandalf, fallible in some ways but still too “high” to relate to on a human level: a great teacher seen through the eyes of a young student. And it is Dumbledore whose character is deepened in the last book. Yes, his trust of Snape is vindicated, which wasn’t really hard to guess. But his family troubles, his brush with Grindlewald, and his final miscue with the Stone of Resurrection finally make him a man and not a mere wizard.
Yes, it would have been nice to have more epilogue, and it seems that Rowling is prepared to supply additional information off-line, so to speak. I’m disappointed to learn that the Elder Wand can’t defeat whatever magic damaged Neville’s parents. But I’m not surprised that Neville and Luna don’t hook up, nice as that would be. Rowling has too much respect for the underlying mythos to allow the faculty of Hogwarts to reproduce physically. Even Hermione has to choose. Wizardry is potent; but great wizardry is also sterile.
As to Douthat’s “just a kid’s book, after all”: he must have read a different series than I did. Yes, Harry completes the hero’s quest and gets the hero’s reward. But nothing comes without a price; as he says, he’s had enough trouble for one lifetime.
Rowling wants to teach her readers not to fear death, but, unlike kid’s-book author, she doesn’t avoid its pathos. Yes, Hagrid is spared, and the deaths of Lupin and Mad-eye’s are emotionally tolerable. But I wouldn’t have guessed that Rowling would kill off Tonks and leave her child an orphan. She’s got some nerve.
Overall, if we compare Harry Potter with Narnia, Lewis easily takes the prize for literary polish, but Rowling’s work is infinitely preferable from a moral standpoint: saner, wiser, and nobler, not least because, unlike Lewis’s insufferably good heroes, none of its characters is flawless.
Update But I have to admit that goblins obviously draw on nasty streotypes of Jews as small, ugly, unscrupulous moneylenders.