Whenever Fabregas' future used to be in question from summer '07 onwards, there would straight away be a statement saying he will stay. The speculation surrounding a move to Man Utd (and perhaps ourselves) has been going for a while now.
Personally I feel if he moves back here, he will only move to Arsenal. But there will be options to move to another league (Italy or Germany) if he wants. I think his first preference would be to stay at Barcelona as long as he'll be a guaranteed starter next season (for most of the big games...not just so he can rack up hat-tricks against the equivalent of Reading in league fixtures).