
Beatty, who is now in his seventies and hasn't been in a movie since 2001, has been in a long battle to reclaim the rights to the character, which he recently won. As slashfilm have pointed out, he doesn't like talking about movies before they get made as apparently that prevents them from becoming a reality, so there could be some credence to his talk of a sequel on the way. Even if he wanted to before, he wouldn't have been able to due to the legal issues.
He hasn't said if he'll reprise his role or recast, but the original movie (itself not the first Tracy movie) had a fantastic cast that included Al Pacino, Dustin Hoffman, James Cann, Kathy Bates, Catherine O'Hara and Madonna. If he did want to continue the first movie, it'd be great if he could attract a similarly impressive roster of stars (although obviously, Madonna couldn't return).