I don't see Amelia being in the bottom 2. Ideally, Craig should be. Whoever is in the bottom with Misha B will get sent home - however I think it will be the last chance the judges will have to keep saving her, next week its all down to the public vote and she'll be out. Unless they fix it to get her into the final, like they blatantly did last year with Cher - Mary would've gone through had they not introduced a "last minute sing off" for the judges to vote her out!
Even if Craig ends up winning whatever fanbase he had during the show will disappear once he gets his album out 9 months later Same with Matt Cardle, Leon Jackson, Joe McElderry. Amelia and Little Mix will go on to have big careers. Runners up always do better!
I actually think they want someone who they can market as the perfect popstar - someone like Amelia or Little Mix to win this year rather than Craig or Marcus. They've only had so many "dud" winners, if they get another, the show's credibility of finding "the next big popstar" will be tarnished.
whatever fanbase he had during the show will disappear once he gets his album out 9 months later 
2 bad her song is very average.....but good performance