Apparently some word has started to spill about the possible Christopher Nolan produced Superman movie. The most interesting news to me is the clear demarcation between the Superman and Batman universes.
Personally, I don't know if that's all that good of an idea. Though I agree that they should definitely have their own universes, I'm not convinced that they should totally rule out a possible crossover.
One of the strengths of the recent spate of Marvel films has been the interconnectedness of them. It's not overt, but it is there. They may never get around to making that rumored Avengers film. But they've left to the door open for it to be possible.
By the same token they need to leave that door open for a possible Justice League film. Though it may never see the light of day, we need the hope that it could. Super-heroes are about hope after all...