There has been rampant speculation that Harry himself--or more specifically, Harry's scar--is the final horcux. The theory goes that, if that's the case, Harry may have to die to kill Voldemort. Part of me wants to brush this off as just plain silly--but is it?
Let's start with one clue that I don't think plays in.
The one with the power to vanquish the Dark Lord approaches... Born to those who have thrice defied him, born as the seventh month dies... and the Dark Lord will mark him as his equal, but he will have power the Dark Lord knows not... and either must die at the hand of the other for neither can live while the other survives.
I've read opinions that say this prophecy means that both Harry and Voldemort must die at the end. I've never been good at word puzzles, but I just don't get it. To me, while this doesn't preclude the possibility that they both could die, it doesn't mean that they both have to die. However, there are many other reasons I think that Harry or Harry's scar could be Horcrux 7.
Dumbledore says that he believed that Voldemort saved the making of horcruxes for especially important murders. What murder could be more important than the murder of the only person who could kill him?
Secondly, what object has been more important throughout the entire series than Harry's scar? It's been right there from day one, and it's the only "object" that's been mentioned that was at Godric's Hollow the night that Harry's parents were killed.
Third--and this is the part that worries me the most--Jo seems to be writting on a Lord-of-the-Rings-Frodo-sacraficed-himself-but-saved-the-Shire theme. Look at how it's run through the book so far--Harry's parents died for him, Sirius died for him, Dumbledore died for him. It's a theme at least as old as the Bible, and it probably goes back much further than that--someone has to sacrafice so that others can continue to live and love.
Although, as I said, it's been a theme throughout the books, I saw it more than ever when Harry told Ginny he couldn't date her anymore at the end of Book 6. The fact is, Jo writes realistically. In a 2001 interview she said, "If you are writing about evil, which I am, and if you are writing about someone who’s, essentially, a psychopath – you have a duty to show the real evil of taking human life." When it comes, the battle between Harry and Voldemort will be the culmination of a war between good and evil. In real wars good people often die so that others can live. Harry dying to save his friends would not be a stretch in the least.
Lastly, Jo has said there will be no more Harry Potter books. Although it's not dispositive, what better way to effectively eliminate the possibility of a sequel.
But, although there are many reasons to do it, please Jo, don't kill Harry!