One of the big changes for next year is teams that finished 3rd in a Champion's League group used to be able to join the UEFA Cup field. That will no longer be the case. You're either in the Champion's League or the UEFA Cup.
I think the number of games in the Champion's League will be slightly reduced next year. I'm not sure of the new format yet. There is concern that players are playing too many games. Well, the first thing that should go is those moronic international friendlies.