In what is admittedly only a rumor at this point, Harry Knowles of Ain't it Cool News is reporting that a "pretty reliable" source has tipped him off about some very interesting Green Lantern movie news. If what AICN is reporting is true, it could be the first sign that DC Comics/Warner Bros. is listening to the fans and taking a page from Marvel Studios' playbook by making GL part of a shared universe, rather than a stand-alone universe like its Batman franchise.
As of now, the only official cast pick is Ryan Reynolds as Hal Jordan, the most popular Green Lantern from the DC Comics series. In the comics, Hal's arch-nemesis is Sinestro, a former Green Lantern twisted by his need for order and control, and the character is expected to be the major antagonist for the feature. According to AICN, that role could be going to Jackie Earle Haley, who famously portrayed Rorschach in Watchmen and will be starring as Freddy Krueger in the A Nightmare on Elm Street relaunch.
And, in news that would trump the Hayley announcement if it turns out to be true, Green Lantern may be visited by at least one other major character from the DC Universe. According to Knowles' source, Superman will make an appearance in the movie. If this rumor turns out to be true, it could be the preamble to the Justice League movie that Warner Bros. has been planning for years, in much the same way Marvel Studios is planning on interweaving characters and concepts in Iron Man, Iron Man 2, Thor, and The First Avenger: Captain America leading up to The Avengers.