The project has long seemed in trouble, with DC Comics trying to catch up with Marvel Studios and their success with the Marvel's The Avengers franchise. Last month, it was widely rumored that Justice League's fate rested solely on the success or failure of Warner Bros.' Superman reboot Man of Steel. Then, it leaked that the studio was very unhappy with Will Beall's script, and that they are currently seeking out a new writer.
Now, it is being reported that Warner Bros. is bringing Christopher Nolan on to not only produce, but also shepherd the project, just as he did with Man of Steel.
This means that Christian Bale may return as Batman, even though he stated multiple times that The Dark Knight Rises would be his last turn as Bruce Wayne. The actor did reveal in a recent interview that, if Christopher Nolan came to him with another Batman story, he might be interested in donning the Bat-suit once again.
It is also being said that Man of Steel director Zack Snyder will produce Justice League alongside Christopher Nolan, and that he may possibly end up directing Justice League as well.
Christopher Nolan is also said to be developing/shepherding all of Warner Bros.' superhero projects from now on, in a role that may be similar to Mark Millar's consulting gig at Fox. Nothing has been confirmed (or denied) by the studio at this point, so consider this information a rumor for now.