My prediction for Deathly Hallows is as follows: Harry finds out that is Scar is a Horcrox and thinks that he must kill himself in order to kill Voldemort. But just as Harry is about to Avada Kedavra himself, Snape runs in. (Snape is really is working for the Order of the Phoenix and has been a spy for them the whole time, he had to kill Dumbeldore to show Voldemort he could be trusted.) Snape tells Harry that there's another way to destroy the last Horcrox of Voldemort, that Voldemort will die but Harry must give up being a wizard. Harry goes along with this and Snape performs a curse to take all magical ability out of Harry. This destroys Harry's Scar therefor killing lord Voldemort. Well there's my dumb theory lol, something like that.