So that one guy on Twitter said that there is this moment between Superman and Batman getting him teary eyed, right? Also listening to the track (Do you Bleed), this is what I think will happen.
-Epic fight, starts with Superman just throwing Batman through walls and whatnot.
-Bruce calculated pretty much every move, eventually he finds a way to weaken Clark. The shot in the trailer with him blocking the punches and head slamming him is where he turns it around.
-Zack said that the suit didn't enhance his power, just bought him more time and taking more damage than actually possible. This leads me to believe that Bruce knows he is fucked and has to take down Superman quickly before the latter gets his full power back.
-He fails, Superman beats him and Bruce feels he let himself and those who died on Black Zero down.
-Enter the soundtrack Do you bleed (the ending part, from about 7.30). Supes holds a speech telling him he does not mean any harm, feels sorry (and kinda responsible) for the deaths of all those civilians but that he'll do anything to make sure something like that never happens again.
-Stretches out his arm to help Bruce up, shot of their arms/hands. Supes pulling him up from the ground.