Can I add my own opinion on who will die in the next book? I think it is Dumbledore. I have read all 5 books in succession (the second time I have read them all), and there seems to be too much discussion about "what would we do if Dumbledore--the only one He ever feared--weren't around to help. I just think it would allow Dumbledore a fantastic death scene in 7 and opening the way for a HP/V showdown in the last book.
Dumbledore is also a "friend" of Harry's. Just my opinion.