Bella's Fate

Every twilighter out there is wondering this question. At least, I know I am. Will clumsy, lovable Bella really turn into a vampire? It is very plausible that she does, but could Edward go through with it? My personal theory is Edward will somehow end up turning into a human instead. I think I would like that alternative much better than ever having to think of Bella as a blood crazed maniac. I was thinking, maybe the Volturi would make some sort of exchange. Maybe, if they made Edward human, than they would want something, or someone, in turn. In Eclipse they offered Alice a position in their guard. Maybe they would be willing to trade. Edward for Alice. It's just a theory. At the moment, I'm at a loss for another alternative. Are there any more unexpressed theories floating around out there?