Hello everyone I come to you with just my thoughts on what should happen with Joseph Gordon Levitt's Character in the Nolanverse, John Blake.
Most people would say they would like to see him play Nightwing in a solo [Nightwing](movie:1069726) film, but I think if Christopher Nolan ever thought of continuing his story of Batman I would think a second trilogy of the Batman mythos, making it about John Blake taking over the role as Batman. The story and be related to the Batman Beyond but have its Nolan twist to it, being the original identity of Batman in the the Beyond series was Terry McGinnis, but nothing is written in stone, it can be changed to John Blake because this is Nolan's world, his own original take on Batman Beyond.
Christopher Nolan would have to direct, it is his Universe after all and he understands it best. He would be the only hope that it this Batman Saga won't turn out like Batman & Robin.
Just like in the original story Bruce Wayne is a huge part, so it wouldn't be the same if Nolan's Batman/Bruce Wayne Christian Bale didn't come back to just play the role of just Bruce Wayne, maybe dye his hair a little gray, and use some make up to make him look a little older, and he would have to have a beard, just because he looks awesome with one.
Finally for villain, if Chris Nolan ever decided to actually do it, he would probably have some villains in mind that he can realistically revamp, like The Joker, Scarecrow, and Bane was. Some villains I had in mind you will see down below.
and my last choice..
Given a little bit of the Nolan touch, we would have a pretty kick ass Batman Beyond movie. Let me know what you think in the comment section below, thanks for reading.