I would say that this is a spoiler right now since I think that this might be true. So spoiler warning everybody.
Remember when Dumbledore said that Harry might be happy that he let Pettigrew live? Well, I have concluded after a large amount of reading, (and a large amount of torturing Rowling) is that Voldemort can't kill Harry. When Harry let Pettigrew live, he created a bond that Peter owes Harry his life. And when Peter poured his own blood to make Voldemort come back, that means a part of Voldemort can not kill Harry. Otherwise, saying, that Voldemort owes Harry his life. See, this is not as bad as the R.A.B. rumor I started.