My personal guess is that the final battle will take place on Privet Drive, at midnight. Since Rowling said we have to expect some surprising things from Aunt Petunia. I say Petunia, having recently started menopause and being crankier than usual, will get out of the house in her bathing robe, yell at all those filthy magic users, and shot the lot with a rifle, actually hurting Voldemort, thus allowing Harry to defeat him.
...
Yeah, not gonna happen, but you have to admit that would be unexpected.
