Yeah, I kinda blanked out on this thing for awhile, y'know how it goes. Anyway, now that I've got some time here's the big theory of mine, the off-showing of which was more or less the purpose of this enterprise. I've got a few other ideas which I'll toss up here periodically between now & July, but this is the only one I'm more or less certain of.
Point one: concerning the artifacts of the Hogwarts founders. From Hufflepuff, we have a cup; from Slytherin, a ring and a locket; from Gryffindor, only one known relic, the sword; and from Ravenclaw, an unknown item. Reading either ring or locket as a reasonable approximation of a coin or precious stone, no very deep occult research is needed to identify the missing part of the sequence cup - gem - sword. The missing item is also something central to the series, something every witch and wizard owns; in fact it's the one item we know
Ravena Ravenclaw must
Point two: concerning Ollivander, the wandmaker, who has gone missing between books 5 & 6. HBP, p106 in the US paperback:
"Talking of Diagon Alley," said Mr. Weasley, "looks like Ollivander's gone too."
"The wandmaker?" said Ginny, looking startled.
"That's the one. Shop's empty. No sign of a struggle. No one knows whether he left voluntarily or was kidnapped."
"Shop's empty" is something to come back to, but for the moment we'll skip to the Hogwarts Express, where Neville Longbottom shows Harry his new wand. p137:
"Cherry and unicorn hair." he said proudly. "We think it was one of the last Ollivander ever sold, he vanished next day -- oi, come back here, Trevor!"
(the last, of course, is directed to his errant toad familiar. That toad bears watching too, but later for that...)
Point three is simply that it feels
right. Putting together the Tarot-suit completion of the Hogwarts artifacts, the disappearance of Ollivander, and the fact that JKR happens to mention Neville's new wand at all, I come up with the one prediction about book 7 on which I'm more than reasonably confident: I suspect one of the remaining Horcruxes to be the wand of Ravena Ravenclaw, and that it is currently in the hands of Neville Longbottom. In the conservatory, with the lead pipe.
Following that, some more speculative footnotes...
Much of the evidence surrounding Ollivander is amibiguous, though it leans toward the sinister. There's certainly something creepy about his "great things, terrible but great" routine, though at least he did throw in the 'terrible' disclaimer. He might have just been trying to impress on Harry a sense of his own potential power. That he gave Harry the twin of Voldemort's wand really can't be read one way or the other -- although it did help later with the Priori Incantatem
effect, it's still kind of off, like giving some kid Hitler's hat.
Then there's what Mr. Weasley said, about the shop being empty. Does he mean there's nobody
in the shop (and is there usually anyone there other than Ollivander)? Or that there's nothing
in the shop -- that it's been emptied? If the latter, that certainly implies
a willing departure. For Muggles this would be a damning point, but for a competent adult wizard it's no great difficulty to pack up and remove a shop's contents in a short time -- assuming the owner and any magical protections on the property had been overcome. On a similar note, it's difficult to imagine that a presumably powerful (and surely well-equipped!) wizard could be captured by force from the middle of Diagon Alley at any hour without attracting notice -- but on the other side of that, nobody ever said that Ollivander lives
in his shop, or even spends much of his off-hours time there.
If the theory about Ravenclaw's wand is correct, it would seem to argue that Ollivander was taken unwillingly -- in that it's difficult to see why anyone loyal to Voldemort would want to slip one of his Horcruxes to a known ally of Potter's, unless perhaps it has some active power of its own as did the Riddle diary. Giving the wand away the day before vanishing implies a planned departure, but that doesn't mean Ollivander must have run off to Voldemort. Realizing his own value as a target, he may have decided to pack up and take a very distant holiday; or more pessimistically, decided it was only a matter of time before They got him and unloaded the wand on the first DA member to come in, coincidentally just before They actually did.
Regardless of Ollivander's loyalties, it seems likely the Death Eaters have captured a depressingly large stockpile of the finest wands. Aside from being able to replace any that are broken or lost in battle, having a lot
of wands doesn't make any given wizard more formidable -- but is it safe to assume that Voldemort is going to keep the whole lot stored in a cupboard as spares? Or could he be planning to provide wands to a whole bunch
of beings who aren't allowed them? Goblins, perhaps?
Edit: after writing the above, I happened to pick up OoTP again this morning; on p85, Arthur and Lupin are discussing goblins:
"I'm sure they'd never go over to You-Know-Who," said Mr. Weasley, shaking his head. "They've suffered losses too. Remember that goblin family he murdered last time, somewhere near Nottingham?"
"I think it depends what they're offered," said Lupin. "And I'm not talking about gold; if they're offered freedoms we've been denying them for centuries they're going to be tempted.[...]"
Now that's interesting, isn't it?