I picked it up on Saturday morning, started it at 10:00 a.m., and finished it at 11:15 that night. (We took a 2-1/2 hour dinner break for my birthday in the evening.)
A few observations:
1. Rowling has the adolescents down pretty well. She has Ron's love life with Lavender Brown down to a T. That's exactly how that age handles love, from what I've seen of middle and high school kids. Their eye-rolling and disdain of teachers is spot-on, especially when it's done behind the teacher's back.
2. Slughorn, the new Potions teacher, is like a few of my past colleagues who gather the "stars" around them and hardly notice the rest. Rowling does a good job with Harry's approach/avoid reaction to that teacher. He realizes he may need Slughorn to get ahead (particularly if he wants to be an Auror), but detests the bottom-kissing he must do. Ultimately, Harry does the right thing and rejects that scene.
3. Dumbledore's death was what I expected, but not in the way I expected (although that may yet turn out to be what happened). I thought he would die to protect Harry; in the book it's kind of indirectly so. Personally, I think he'll come back. There's something about that tomb; no other Headmaster has one like it, or at least I presume so as other tombs have never been mentioned. Dumbledore may now be in a different form- a ghost, like Nearly Headless Nick, who can still advise Harry and be part of what's going on in the world in spite of not having a body.
4. Harry has finally gotten the right girl in Ginny Weasley. Expect Ron to hook up with Hermione in the final book, but it may not stick. It would be just too neat to have the four of them become two couples.
5. Snape... I think this is still Snape under deep cover. It goes with the idea I have that Dumbledore is not really dead. It was just too improbable for the Death Eaters to get into Hogwarts and do so much damage (and get away). Was it part of the Order of the Phoenix's plans?
I haven't hung out at HP websites to hear what the real fanatics are saying, but it would be fun. Now I'm waiting for "Goblet of Fire" to arrive in theaters this November!
As you can see, I'm a big fan myself. I've been a fantasy/sci-fi fan since I discovered LOTR in my sophomore year of high school. Right now I'm reading a John Varley sci-fi adventure called "Red Thunder". He's a favorite of mine.