@tempest: I mean at first, Voldemort didn't know that harry was horcrux, because of the flying horcrux spell, he didn't know what it hit, OR he could of just forgot about it seeing as his soul was just being ripped from his body, a horcrux spell would be something i would forget about. Anyways, after trying to kill him again and again, he finally realised that Harry is a horcrux(probably sometime after CS) and he then tried to back off Harry a little, then in GOF, harry almost foiled Voldemort's plan again, THEN in at the department of mysterys, harry BROKE the prophecy and ultimately defeated a hord of Death Eaters with a few Stupify and Expelliarmus spells, so Voldy finnaly got mad enough to where taking out a piece of his soul would be a small sacrifice so at least 2 of his plans could go without interruptions
also, who ever said that killing the holder of the horcrux would take out the horcrux too, i can see a dead body as a horcrux