What I'd love in this game is challenge maps like those in AA and AC. Yes, maybe you think now that it's taking too much inspiration from those games, but in my opinion, if it makes the game funnier then why not?
They could add more to it, such as time races (that you can save when completed to watch again later with other camera settings, to watch your cool Web Rush stunts from another perspective), Resque challenges, Boss challenges etc.
I also wonder if there will be cool collectibles in this game. The riddles in AA and AC are great to show the cool history and rogue list of Batman. Obviously, you can't have riddles in ASM, but it would be cool if there's something else that is reminiscent of it, like you can find Daily Bugle newspapers that unlocks character bio's for you or something. I'd love if they have some Easter Eggs in the game as well.