If they do another one, I think it should be that a new villain is making it hard for Gotham's new protector, Robin, & he and Alfred find a way to get in contact with Bruce and bring him back as Batman.
He goes against Selina's wishes for him to stay away &, in a confrontation with said villain, Tim Blake/ Robin is killed, leading to Bruce making it into a personal vendetta to stop this guy/ chick.
I don't know what villain to use, or where to go from there, but by the end Seliina would officially start her rivalry with Batman as Catwoman & Bruce would get his old life back somehow.