Will next ‘Potter’ book answer these questions?

Who will be the next Defense Against The Dark Arts teacher?
No other subject at Hogwarts has been so rough on its instructors as Defense Against the Dark Arts. None so far have lasted more than a year. Harry himself unofficially took over the post in the last book, but with Dumbledore back in charge, a real teacher will almost certainly be appointed — and assuming Rowling doesn’t plan to bring in a new character again, it’s probably about time to accede to Severus Snape’s longstanding desires and give the job to him.

Just what role will Neville Longbottom play in the resolution of the series?
When introduced in the series, Neville seemed little more than a pathetic, nerdy bit of comic relief — a nervous, overweight and somewhat foolish character henpecked by his grandmother and unlikely to amount to anything. But over the course of time Rowling has revealed both hidden strengths in his character and hidden secrets in his past that make Neville’s journey as a character perhaps the most interesting in the series.

In the last book, we learned that his powerful parents were driven insane by Death Eater followers of Voldemort — one of them, Bellatrix Lestrange, was a cousin of Harry’s godfather, Sirius Black. We also discovered that Neville, rather than Harry, almost became the child who would gain the magical power to defeat Voldemort, and that it was seemingly a chance decision on the villain’s part that sealed all their fates.

As a wizard-in-training, Neville has also grown from uselessness into one of the fastest-learning of Harry’s Defense Against The Dark Arts students, which is partly due to his parents’ lineage, and surely partly due to Neville’s determination to help defeat Lestrange and her brethren once and for all. Neville clearly has a larger part to play in the series, and very possibly a crucial one.

Who — if anyone — will die in this book?
The two main sources of speculation about the plotline of "Half-Blood Prince" have revolved around, first, the question of just who the half-blood prince is, and second, a rumor that a major character was going to be killed off in "Prince." On her Web site, Rowling confirms that death will haunt Hogwarts again (“Yes. Sorry.”), but offers no further information.

I’ve already made my guess based on whose removal I think would hurt Harry the most, since it seems like the series’ dramatic arc will require that at the end of the penultimate book. But because I don’t want to ruin the story for anyone if my guess is right, I’ll keep my speculations to myself. (As for who the prince is, I can’t say I’m not curious, but I’m not too worried that Rowling won’t resolve that question. It’s the title of the book, so she probably won’t forget. She has already revealed that it’s not Harry or Voldemort, however.)

Will Harry or the other characters time-travel again, as they did at the end of "Prisoner Of Azkaban"?
I hope not. Although Rowling used it cleverly to resolve the events of "Azkaban," time travel is the kind of thing that can quickly get in the way of the story, needlessly convoluting things and making it a real drag to figure out what happened when, or whether it really happened at all.