Keith Olbermann at msnbc has pieced together his own theory of how the book ends. He bases a lot of it on financial concerns, but his final theory incorporates a lot of my own theories and put a spin on it I hadn't thought of. Here it is:
(I'll put a little space in here in case you don't really want to spoil the ending.)
So why not this ending? Harry eliminates all but one of Voldemort’s horcruxes. The dark lord’s life is now reduced to this undulating welt on Harry’s own forehead. To kill Voldemort, Harry must kill himself and is about to, as millions of readers recoil in horror and anger, when who steps out of the shadows but Snape to explain to Harry that there is another way that the last horcrux, Harry’s scar, can be removed, but at one dreadful price. Harry can survive it, but his magical skills cannot. To finally vanquish Voldemort, save Hogwarts and Hermione and Ron, and, in fact the magical world, to say nothing of the J.K. Rowling franchise for decades and generations to come, Harry Potter must give up being a wizard.
So what do we all think?