TodayShow.com has a brief interview with Daniel Radcliffe. In that interview, the reporter asks him whether his character, Harry Potter, will survive The Deathly Hallows. His response:
I think I might die in it, but that’s just my prediction. I think so, but I’ve no idea at all. I have no inside hints.
I would be very surprised if that happened. This is, after all, a children’s book. It would also be quite a turn-around from how all the other books went. That’s not to say that I don’t think there will be deaths in the book. I’ve talked about what I think is going to happen in book 7 already. I would be very surprised if Harry died at the end.
If Harry did end up dying in the last book, killing him in the last book would end up sinking the series long term. Instead of being a classic children’s story, very few people would read all seven books knowing that Harry died at the end.