According to Deadline via Aintitcool, Christopher Nolan is being asked for a huge favor by the heads of Warner Bros. God I hope this is true.
"Our insiders say that the brains behind rebooted Batman has been asked to play a "godfather" role and ensure The Man Of Steel gets off the ground after a 3 1/2-year hiatus."
Referring to Nolan's forthcoming Warner title INCEPTION:
"While Nolan completes that Leonardo DiCaprio-starrer for a July 16th release, he's also hatched an idea for Warner Bros' third Batman installment. Now his brother and frequent collaborator Jonah Nolan, and David Goyer who co-wrote Batman Begins and penned the story for The Dark Knight, are off scripting it."
[EDIT]
"As one of our insiders reassures: “It would definitely not be a followup to Superman Returns."
http://www.aintitcool.com/node/43932