Unboxed Spoilers, for those who have not read through The Order of the Phoenix.
Rowling has been coy as to whether Harry will survive the series. I don’t think he’ll die. The prophesy said with regards to Lord Voldemort that “either must die at the hand of the other”. While this doesn’t mean that both of them survive, I think Harry will.
Harry Potter is one of the most beloved characters in literature. The books are read by countless children. Can you imagine the trauma they’d go through it Harry snuffed it? Rowing would become The Most Hated Woman In England. Parents would be clamouring for her head on a silver platter, with a side of fries. It could destroy her career.
But is Harry “The One”? Neville Longbottom also fits the terms of the prophesy, with one exception: “[T]he Dark Lord will mark him as an equal…” Neville hasn’t been so marked. (i.e., Voldemort hasn’t recognised him as a threat.) He has Marked Harry, and he has marked Harry. Consider this, though: Rowling has been very careful in her stories; from the choosing of names, to continuity between the books. In The Order of the Phoenix she mentions Neville as possibly being the one who will vanquish Voldemort. Why would she mention it, if she wasn’t going to use it later? It would certainly fit with her style of having people be other than they appear.
I’m guessing that somewhere along the line, Voldemort will notice Neville. He’ll “mark him as an equal”. Then we will not know if Harry will kill Voldemort, or if Neville will. Either one of them could be expendable. As I said earlier, I don’t think she’d kill Harry. Too many readers have been vicariously experiencing his adventures, and they have invested too many emotions in the character. But Neville being the hero would fit with her “twists”, as I said. I think that Neville will kill Voldemort, saving Harry in the process. Since the prophesy doesn’t say whether one will live, it’s possible that Neville will die in the act. But I don’t think so.
I think both Harry and Neville will live. When Neville becomes the hero, Harry will lose a lot of the unwanted attention he’s been getting over the years. He’ll be able to live a “normal” life, free of much of his celebrity status. Neville, the clumsy lad people make fun of, will get the glory he’s missed out on all through school.
Harry has said that he’d like to be an Auror. Hm. If Voldemort’s dead, what’s the point? Mopping up? His real love is Quidditch. Maybe he’ll go on to be a professional player. Maybe not. I can’t see him being happy doing that. He’ll be too young to be the Headmaster after Dumbledore dies (which I think will happen at the end of Book Six). I have an idea that he’ll become a Professor at Hogwarts. I think Dumbledore will be replaced by Professor McGonagall.
What about the relationships? Ron and Hermione seem destined to be together. I can see Hermione and Harry together too; but I don’t think it likely. Maybe he’ll wind up with Ginny? Or maybe someone else will be introduced. I have a hunch it will be someone we’ve already met though.