First thing that got me was that everyone's theories were so totally wrong outside of possible deaths and the final horcrux (although it wasn't necessarily his scar, so much as it was Harry himself).
I'm going to have fun reading the mugglenet.com book with predictions on Book 7. (I got it from the library. It's on my shelf right now!)
I was afraid that he'd get a 1-on-1 showdown like GoF instead of big battle like OotP, and the plotting (or was it "plodding"??) through the woods gave me a bad feeling. I wanted to know where everyone else was and I didn't care about these new (or at least unimportant) people that kept showing up in the middle of the book.
Anyway, we got an ending that not only made OotP look like a playground scuffle at recess, but it was reminiscent (I tired, I know I spelled it wrong) of The Battle of Five Armies in the Hobbit (or were there Six? Oh, who could keep track -- there were so many!)
On the deaths, I predicted Snape, but for the wrong reason, and either Fred or George, but not both. I figured that a Weasley would die and it wouldn't be one that Harry had already saved. That left Fred, George, Percy, Bill and Charlie and the mother. Bill's already been damaged, so scratch him. The readers really only had a vested interest in Fred or George, so it had to be one of those two. Percy's death wouldn't have meant as much.
I would have liked to have seen an epilogue that let us know what happened to more of the characters, particularly some of the minor ones, in the aftermath of the big battle, but I guess we should be happy with what we got. Maybe Jo could be convinced to write a novella for some charity.
I knew that Dumbledore wasn't a dupe and we finally found out why he trusted Snape so much. Lots of other cool stuff that I'm sure has already been mentioned.
But in the end, at its core, it remained a children's fantasy story, when love conquers all. Not only that, but a Mother's love: Lily, Mrs. Weasley, and even Narcissa.
And here's one other tidbit that I looked up because I was curious:
Weasels are mammals in the genus Mustela of the Mustelidae family.
The otter (lutrinae) is a carnivorous aquatic or marine mammal part of the family Mustelidae, which also includes weasels...
Should've been obvious.
One prediction I had that panned out was that the “awful” boy that Petunia talked about in OOtP would be Snape and not James. That turned out to be right. Poor, pitiful Snape
Ms. Rowling wrote the epilogue very early--maybe even before book 2, and apparently felt that 'artistic integrity' required that she publish it as it was written then. Although she'd decided on a few things that needed to happen between Book 1 and the epilogue, most of the intervening characters and plot were thought of later and thus played no role in her eplilogue.
Frankly, I would have liked her to at least have filled in a few blanks before publication, such as kids' middle names. I think James Sirius Potter would have had a nice sound, wouldn't it? His daughter could perhaps be Lily Tonks Potter. Who cares if Sirius and Nymphadora hadn't been invented when the epilogue was first written? I'd suggest Rose Grainger Weasley and Hugo Remus Weasley for Ronald and Hermione's kids.
I don't know if anyone has posted it yet, but JKR is intending to write an encyclopedia. From what I gathered from her interview (Today show? CBS? This morning, anyway) she had wanted to include a proper epilogue in the book, including the usual "where are they now?" but for all the central characters. I think that is part of her goal with the encyclopedia.
BTW, also not sure if it has been mentioned yet: She told one young fan this morning that Harry and Ron went on to "revolutionize" the Auror department, and that Hermione became quite an important figure in Magical Law Enforcement. Not the future I would have planned for Hermione.