I should have realised that something was amiss when my main reason for wanting to get a hold of HBP quickly was to be sure to avoid spoilers. When OotP came out, I eagerly went and queued up for it, and then read it al immediately after getting home, without breaks. This time, I went out and bought it with little enthusiasm, and had no problem putting it down and going to sleep in the middle.
In a lot of ways, this is reminding me of The Phantom Menace. I'm trying really really hard to convince myself that this was god, and that the magic is still there, but deep down in my heart I know that it isn't. It's not as if the warning signs haven't been there since GoF at least, but I have to say that I've finally stopped caring about this series.
Now don't get me wrong, it was still an enjoyable enough read. And I'll still buy and read the next one, probably very soon after its release for fear, once again, of spoilers. That's not saying a whole lot though: I'm still reading Terry Goodkind's Sword of Truth novels, and they've been jumping whole flotillas of sharks every novel for about the past six. I've got this far, and I want to know what's going to happen next, especially with the end in sight. I just can't see myself getting excited any more.
The problem, I suspect, is that Rowling has grown to believe some of her own hype. If she'd come up, ten years ago with a 600+ page version of PS, then she'd have been laughed at and probably never even got her transcripts read, let alone published. The first three novels in the series were very tight. They told the stories they were meant to tell, with no extraneous detail, and they were better as a result. Between PoA and GoF, though, she got Big, and now Bloomsbury would happily publish Harry Potter and the Phone Book Recitation or Harry Potter and the Unfortunate Case of Flatulence because people would buy them.
So now we have books where it's generally safe to skip the first 100 or so pages because nothing seems to happen in them, and where the actual underlying story could be told in about half the space. People ask how they're going to manage to make sensibly-lengthed films of the latter books, and the answer would seem to be obvious: they're going to cut out all of the extraneous crap (which will no doubt have various fans up in arms).
GoF at least managed to have a well defined plot. It was about the triwizard tournament, and there was clearly something fishy going on with it, and at the end we discover what it was. Wonderful. OotP was much more rambly. It was clearly "one out of a series" and didn't really paint a cogent whole. There was the stuff with Umbridge, and the DA, and the Order forming and the Ministry being stupid, then the cataclysmic end battle and the incredibly inane prophecy.
And yet, I was willing to forgive OotP, for several reasons. For one, it felt transitional between the earlier books and what was to come. For two, the ending was actually exciting (if you lop off the prophecy bit). For three, it seemed to be moving away from just the Trio, and introducing new characters and expanding on the old ones.
HBP didn't even have any of this to recommend it. We were back to a very trio-centric book, with an extra added role for love-interest!Ginny, and there was even less actually happening in this one than in OotP. The stuff about Voldemort's history was interesting, but it could quite easily have been relegated to an appendix, or even an entirely different book, as it seemed to have little bearing on the rest of what was going on. It was back-story that Rowling had wanted to include in CoS but hadn't been able to, for lack of space. She should have learned from this.
The Malfoy parts of the plot were in no way paced at all. it was just a case of knowing that he was up to something right from the start, then throughout the book saying "still up to something" "yup, still up to something" "you haven't forgotten about Malfoy have you". There were no hints and no unraveling of what was going on, so by the end when we learn the truth, it's just a case of "oh, so that's it. ok" rather than any great sense of excitement at a mystery resolved.
Then the actual bits with the Half-Blood Prince himself. Did anyone actually care about that or find it interesting? Because I know that I sure as hell didn't. When it was finally revealed that he was Snape, I just thought "Yes, yes, very nice. And we care about this why?"
And then there was the death of Dumbledore, which was entirely telegraphed and predictable and in no way surprising or interesting.
And the relationships. I'd like to believe that these all looked like train-wrecks because that's how teenage relationships generally work, but given that the adult relationships were jus as hopelessly cringeworthy, I'm going to presume that it's actually because Rowling can't write romance for toffee. This is not a crime, of course, but it is an indication that you should try to avoid pairing off all of your characters.
The most interesting thing to happen in the whole book was Snape's betrayal, and that's tempered massively by the fact that there are clearly and obviously plot twists still to come on that front. (See rahaeli's entry about just that (Edit: Or don't. It's a friends locked entry, which I hadn't realised/thought of. Sorry).)
It's not that it was all bad, or anything. I generally enjoyed reading it. I just can't bring myself to care any more.