On the Book Seven Title
So now we know: It's Harry Potter and the Deathly Hallows.
This of course leads to the question-- as I've seen discussed on a few other people's LJ's already: "What exactly does she mean by hallows?"
The first point to make stems from a misunderstanding of the term "Hallowe'en" ("All Hallows' Eve"). The term as used here does not refer to the souls of dead people in general. The medieval church holiday system celebrated (and present-day Catholicism still does celebrate) "All Souls Day" on November 2, and "All Saints Day" on November 1. "Saints" here refers to the departed faithful who are believed to have already attained heavenly bliss, while the November 2 holiday honors the faithful departed who are believed to be still atoning for their sins in Purgatory. (As far as I know there is no holiday to celebrate the unfaithful departed!)
A search of dictionary.com doesn't show any noun meanings of "hallow" or "hallows" that would be possible senses here. peachespig cites a couple of meanings from the OED: "a holy person, a saint" and "the shrines or relics of saints or of heathen gods." The first of those definitions is the one that has filtered into our term "hallowe'en" via the "All Saints" holiday. The second of these also carries the "holiness" root meaning, but with the sense of "holy object" or perhaps "holy place." (Note that the phrase "Hallowed be Thy name" in the King James translation of The Lord's Prayer carries the meaning of "May Your name be recognized as holy.")
I can most easily imagine the "holy place" meaning as pertaining to the Book 7 title (are we going to call it "DH" now?). One analogy that comes to mind-- although he uses "hallow" as a verb-- is Lincoln's Gettysburg Address: "We cannot hallow this ground; the brave men, living and dead, who struggled here have consecrated it." To refer to the battlefield at Gettysburg as a "hallows" would, I think, make good sense (it would be a secular adaptation of the term; but to some extent JKR would be doing the same).
I don't at all think the term in Book 7 will refer to Godric's Hollow; indeed, I think that would have been more likely had it not involved a pun like that! But it is true that, from Harry's perspective, Godric's Hollow is sort of a hallows.
What I'm imagining is Harry's final confrontation with Voldemort taking place at some ancient magical site, one having some association with death. Further details are beyond my present ability to imagine. But we'll see what JKR comes up with. (And, although a late-summer release still doesn't seem better than 50-50, I do think it's quite likely that we'll at least have the book by Christmas 2007.)