Agreed that the Nolan films, good as they were, ruined the chances of doing DKR properly. (You can rent the animated version though!)
This wounds me deeply, as outside of Watchmen and Swamp Thing, I feel DKR is far and above the best thing to ever come out of the DC universe. It would have been an epic, brutal live action movie.
As far as re-casting the part, I reject that totally. If Bale is dead set against reprising the role, you go straight to JGL. Otherwise what was the point of that whole last movie?