I think Harry is a Horcrux. He can be because he doesn't have to kill himself and then Voldemort. He can destroy all the other horcruxes along with Voldemort first and then do himself in. Nor would Voldemort mind killing Harry because he's got more than one Horcrux. And Voldemort would be willing to sacrifice a piece of his soul in order to kill the only person on the face of the planet capable of killing him. Not to mention that to Voldemort's way of thinking nothing is worse than death which, to him, means that Harry cannot destroy him.

Moreover it would be just J.K.s style to kill Harry off at the very book seven. It would fit somehow. And Harry would get to meet his Mom and Dad, and see Sirius and see DD again. I honestly do not see Harry living on after book seven.

In addition to all that this would explain Harry's ability to speak Parseltounge. It would also explain why he has the ability to see into Voldemort's heart and mind when he's asleep and Voldemort isn't doing occlumency against him.

I must admit that I haven't felt this sad in a long time.