For several years now, a batman vs superman film has been rumored, but has never come to fruition. Dating back to 2001, the film came to be after a JJ Abrams script rebooting the superman franchise was shelved. Abrams' film had nothing to do with batman vs superman, but rather an origin story for the man of steel. Andrew Kevin Walker, however, pitched the idea of a batman vs superman film and Abrams' idea was shelved.
In 2002, Akiva Goldsman wrote a draft for the potential batman vs superman film that depicted a Bruce Wayne retired from being batman and dealing with the deaths of Dick Grayson, Alfred Pennyworth and Commissioner Gordon. Clark Kent had divorced Lois Lane and was Bruce's best man at his wedding to a woman named Elizabeth Miller, who was tragically killed by the Joker on their honeymoon. This led to Bruce Wayne putting on the cowl and cape once more, and thus setting the stage for the batman vs superman film.
Matt Damon was one of the choices for either role in this projected batman vs superman film. Director Wolfgang Peterson wanted someone who could really act, citing Tobey Maguire from the Spider-Man films as reference. Other actors considered included Johnny Depp, James Franco, Colin Farrell, Paul Walker and Jude Law. The studio approached Christian Bale to take on the role of batman in both this film and batman: year one, which he ultimately chose and was renamed to batman begins, and Josh Hartnett for Superman.
The batman vs superman film was supposed to begin filming in 2003 with a summer 2004 release date. The film was to serve as a reboot for both popular, but all but dead franchises. However, Peterson left the project to direct Troy, and instead of finding another director, the studio shelved the film and went ahead with batman begins, and then superman returns, one of which went on to critical acclaim, the other being a bitter disappointment.
In the Will Smith driven film I Am Legend, there was a billboard with both the batman and superman symbols on it, which led many people to believe that the long rumored batman vs superman film was coming down the pike. But as it turns out, it was an in-joke by Goldsman, who also wrote the script for I Am Legend. So as it stands now, the batman vs superman film is not going to happen, or at least not anytime soon, much to the chagrin of fans long awaiting the groundbreaking film.