as soon as i finished the book, i thought that harry's scar was a horcrux, dumbledore said that voldemort would have made one on the night he tried to kill harry but something went wrong so the horcrux is the scar and its what gives harry some of voldemorts powers and the mind connection, but i dont think he will have to kill himself to kill voldemort, but we do know that the last word of book 7 is scar, and dumbledore was wrong when he said that the sword was the only thing left of gryffindors, the sorting hat also belonged to godric gryffindor, oh and i think jk rowling said godrics hollow was important as a name, so i think harry will definitly find a horcrux there