Believe it or not, I would actually like to see them tie the Nolan trilogy into a Justice League film and have Joseph Gordon Levitt become the new Batman. Hear me out here, before you start ridiculing me.
SPOILERS AHOY, BY THE WAY!!!!!
At the end of The Dark Knight Rises, we had Robin John Blake (known by his middle name, John) inherit Wayne Manor and be given directions to the Bat Cave. I won't go into all the issues with this, and how Wayne would be found almost immediately living alive and well with Selina Kyle in Florence (given his status as a billionaire playboy), because others already have done. The point here is that he has the basic physical strength (as a cop), the basic mental attributes (as a detective), and the resources (via his inheritance) to be able to take up the cowl. However, these are the basics. He doesn't have the ongoing wealth source, so will have to rely on the remaining funds siphoned off by Morgan Freeman, playing Morgan Freeman, playing Lucius Fox, from Wayne Industries in order to fund the overheads to keep the Cave running and power the equipment. He still doesn't have the years of training or experience that Bruce Wayne had though, so he'll struggle noticeably.
Overall, the potential is there but as the trilogy was grounded in (relative) realism, it doesn't make a massive amount of sense. Therefore, I see a Justice League movie where the main heroes EXCEPT FOR BATMAN are involved (Superman, Wonder Woman, Auaman, Green Arrow, and no-one else to start off. Maybe Green Lantern if they can make a new film that's actually good, though I'd say they should still keep Ryan Reynolds in the role if he can be a slightly more serious version of Hal Jordan...). Batman isn't a part of the group, but when Bat-Blake ends up trying to get involved he soon realises he's way out of his depth, something the likes of Jim Gordon already realise due to his mainly taking down small fry in Gotham rather than bigger villains as Bruce Wayne did.
In my vision of the story, each of the Justice League will have had their own origin movies already. As such, I see Justice League (the movie) as effectively being partly the second half of an origin story for the John Blake Batman, the first half having been The Dark Knight Rises. During Justice League, in my idea, Blake will finally realise that he's out of his depth and end up enlisting the help of the other Justice League members to deal with a larger threat, through which they see his potential and decide to train him. The training itself would be a slow and ongoing process as a side story to the main plot and villain, but would ultimately have Blake acting as an effective and skilled successor to the cowl. He still wouldn't have the same skills and abilities as the Bruce Wayne Batman, but would eventually develop to that extent (from the Begins level of skill through to the Rises level of skill that fought Bane) over the course of further films in the continuity. An ongoing character development story that shows the rise of the new Batman despite the early struggles.
With this, we get the Justice League movie we all (presumably) want to see, we get a realistic and sensible character arc, and we get to see the existing Batman film cycle become a part of that mythos which eliminates the need for a new Bruce Wayne and a rehash of the same old origin that Batman always has. Plus, we might get to hear Joseph Gordon Levitt say the infamous "Goddamn Batman" line, which would be pretty awesome ;D.
Obviously the concept requires a lot of tweaking, but this is just a rough idea of what could be done. If anyone else has any ideas or comments, please, I'd love to hear them
