The biggest, sloppiest rumor you'll hear today is Warner Brothers attempting to quietly revive a Superman/Batman movie. You may remember that director Wolfgang Peterson was on track to direct Superman/Batman way back in 2002. Someone pops up every two years reminded us that it's "still happening," but I'll be willing to believe this current rumor more than I'll believe that Wolfgang Peterson is still working on his project. That said, if this actually happens, I'll eat my underwear Herzog-style.
The rumor is that WB is developing not one but two different movies here, all dependent on who winds up showing up. If Christian Bale returns as Batman, though he's rather famously mentioned that he won't make another Batman without Christopher Nolan at the till, the movie would be about the veteran Batman mentoring the newly minted Henry Cavil as Superman. If Bale doesn't return, it would be the veteran Superman mentoring a new Batman, played by some different actor.
I'm not a fan of this story. One of the great things about the Superman/Batman relationship is that they are both contemporaries, two men that fell into superheroics at about the same time. Their friendship came from the fact that the two have fairly complimentary personalities and approaches toward fighting evil, not because one was mentoring the other. I'm always holding out hope for a Superman/Batman movie, but this seems like the wrong approach, What would you guys like to see in a silver screen meeting between DC's two biggest heroes?