Re: Once Nolan's trilogy ends..
Realesticaly you want to have some sort of gap between a new interpurtation of Batman. I would say at least 5-10 years. So maybe sometime around 2018.
It might be hard to top the Nolan Bat flicks, by allowing time to passs they fade somewhat from the general public consious and it allows anticpation to build for a new film.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.