Without access to drawing table, word processor, or internet, I finally had no capacity to do any of the stuff preventing me from reading Harry Potter and the Half-Blood Prince, so I did so. Non-spoiler reaction: There were no real surprises in this book, but it was a much more entertaining read than Goblet of Fire and way better than Order of the Phoenix. Like orders of magnitude better. Still not on par with Chamber of Secrets or Prisoner of Azkaban.
Before reading this book, I had made a handful of predictions, and they all pretty much turned out right.
The first was that Dumbledore would die either as the climax of book six or early in book seven. Check. He's got to be out of the way so that Harry is "flying with no safety net," so to speak.
The second was that Harry would end up with Luna or Ginny. Check. Although Luna was the one I would have bet on, Rowling is basically a cozy romantic hobbit of a woman at heart, so I figured that Ginny's schoolgirl crush in Chamber had a good chance of coming to fruition later. It also keeps that "all in the family" feel ... Harry and Hermione are going to end up as Weasely-in-laws, assuming Harry survives the end of the series.
Before I read the book, I saw a bunch of posts on my LJ-friends list that said re: the ending, "Heck of a death, at the hands of somebody you trusted with your life." That told me, "Okay, Snape kills Dumbledore." Then, early in the book, Snape makes the Unbreakable Vow with Narcissa and Bellatrix, which sealed the deal for me. Not knowing what Draco had been tasked with, I knew at least that it couldn't be anything good, which meant that Snape was definitely EEeeebil after all, which confirmed the spoiler. So as I say, the ending was not a surprise. The main surprise was that Dumbledore's reason for trusting Snape was still never adequately explained. Hopefully it'll be in the next book ... otherwise it'll just be a hole.
I currently only have one prediction about book seven: the mysterious R.A.B. who snagged the Cave Horcrux = Regulus Black, Sirius' supposedly-dead brother, snagging it either before he died, or he is still alive and in hiding (foreshadowed by Dumbledore's speech to Draco about "we can make it seem like you've died and nobody will know you're still alive"). Some broader things are that I suspect there will be some kind of two-face/two-heads motif (possibly in expansion of the Snape explanation) and that Ron is going to take quite a beating.
That's all for now; I wonder if I have enough energy left to draw a strip for tomorrow? Unfortunately, I'm leaning towards "no" at the moment. 11+ hours in the car this weekend, after a hellacious work-week, le sigh.
Edit: I know for a fact that people all over my friends list were talking about this book, but now I can't seem to find anybody's entries about them, with the exception of indigoskynet. So now I guess I'll never know what all that commentary I avoided was, alas!