If he returns, have him pop up in someone else's book. Make him the focus of a Green Arrow arc or something and use that as an excuse to bring in a Bat-Family character in order to deal with him. Use that as build up until he makes another solid return in a Batman book.
Ooooooh I like this idea.
It can't be Superman because of Injustice being too recent still (to me, at least -- I love the story, don't get me wrong).
It can't be GL because he's still in space and seems like he will be for the foreseeable future.
It could be Flash. Actually that would be really cool. Flash vs. Joker.
Green Arrow could work. New creative team and all that? Good time to make sure sales don't dip with Lemire's run (sadly) ending.
Wonder Woman would be interesting but nothing special. She doesn't really have much to lose currently besides Superman and Joker isn't taking down Superman.
Aquaman would be...unique.
You know what? He should just be in Justice League. I'm not really looking forward to Johns writing him in that scenario...but that would be a really interesting story. Just him taking revenge on Bats through the League...