My best friend promised to get me the book, and I don't want to be ungrateful and get it sooner, so I probably still have a couple weeks until I get my hands on it. (so I'm staying far away from this thread after midnight!)
I think Harry is going to die, most likely sacrificing himself. I used to think Ron would do that, but now I'm leaning more towards Harry. I don't think they're going back to school. I think Bill's going to be kind of wolf-y. Neville's going to be important, too.
I think we'll find out why some dead people can come back as ghosts while others, like Harry's parents cannot. And remember that mirror in the fifth book?? I think that's going to come back somehow.