Re: What's next for Batman...
Hmm. There would be risk involved in returning to the Nolan-verse, and in bringing back the character of The Joker, but I don't think the risk would outweigh the potential reward to a significant enough degree to stop them from doing it if they so chose.
I do think that the risk associated with both ideas (returning to the Nolan-verse and bringing back The Joker) would be effectively and significantly minimized, though, by using the setup that Nolan provided to finally bring a variation of Batman Beyond to the screen.
Starbuck: We're all friendlies. So, let's just... be friendly.
"There is no 'supposed to be.' It's an adaptation, a word that literally means change. Why bother making a new version if it doesn't offer a fresh approach?" - Christopher L. Bennett