As Christopher Nolan hits the promotional trail for The Dark Knight Rises, the 41-year-old auteur is hinting that he may soon hang up his superhero cape for good.

Nolan has hastily dispelled rumors that he was planning to direct a film version of The Justice League, Warner Brothers' (TWX) superhero-laden answer to Disney's (DIS) The Avengers, which has pulled in $1.45 billion worldwide since its release on May 4.    

I've got no plans to do anything more and, certainly, no involvement with any 'Justice League' project, Nolan said in an interview with the Associated Press over the weekend.

The director added that, after an exhaustive Batman trilogy, he has said all he can say about the Caped Crusader. Batman will outlive us all, and our interpretation was ours, he said. Obviously, we consider it definitive and kind of finished. The great thing about Batman is he lives on for future generations to reinterpret, and, obviously, Warners will have to decide in the future what they're going to do with him.

The increasingly ubiquitous superhero genre owes a great debt to Nolan, whose 2005 Batman reboot, Batman Begins, breathed new life into a franchise that was left on life support after Joel Schumacher's critically savaged Batman & Robin in 1997. Eschewing the stylized camp and one-liners of that film, Nolan opted for a darker psychological study of the title character's origins. The results helped Batman Begins marry the superhero genre's vast commercial prowess with widespread critical acclaim in a way that had not been previously seen. Roger Ebert called the film the Batman movie I've been waiting for; more correctly, this is the movie I did not realize I was waiting for.

Nolan's follow-up to that film, The Dark Knight, not only earned the late Heath Ledger a posthumous Academy Award for his portrayal of the Joker, but also went on to become the 12th highest-grossing film of all time. However, given Nolan's roots as an indie director, it would be no surprise if his next project were a little less commercially ambitious. Nolan's 1998 feature debut, Following, was produced on a budget of $6,000, which would not even cover catering on The Dark Knight Rises. So far, though, the director has not given many specifics about his post-Batman career.

While still in its early stages of development, The Justice League is expected to feature several of the most popular characters from the DC Comics (TWX) catalog, including Superman, Batman, Wonder Woman, the Green Lantern and Aquaman. The 2007 writers' strike derailed the film's development, but the success of Disney's The Avengers has increased speculation that Warner Bros. will push for a green light sooner rather than later.       

The Dark Knight Rises is due to hit theaters on July 20.