I have mixed feelings on this one. Loved both AA and AC (based losely upon No man's land). But the problem is that The Batman is so vastly different than the other JL members. So significantly different combat mechanics will need to be included for each and every member. While The Batman goes Fisticuffs with the baddies, Supes would mop the floor with the normal scum that The Batman fights. And although The Batman could probably come up with some way to defeat baddies on the order that Supes fights, it wouldn't be Mano-e-mano in a straight fight. Same for GL and WW and just about all of them. Ok, maybe not so much with GA, but...
Still, The franchise has done pretty awesome to this point. So maybe they can pull it off.