Saying that James Cameron's "Avatar" has been a success is something of an understatement. The movie has become a global phenomenon, raking in an astonishing $2.5 billion, which has made it the highest-grossing film of all time. In doing so has broken the record Cameron previously held with "Titanic."

It's not surprising, really, when you think that work on the movie originally started in 1994 and was intended for production after Cameron completed "Titanic" in 1997. However, due to the limitations of the technology at the time, Cameron made the decision to put the project on hold until computer technologies advanced to the point where his original vision could be realized.

From that point on, the director accepted only a handful of projects that captured his interest while development work continued on the "Avatar" concept. And now that the movie has finally been released and has been widely accepted by movie and science-fiction fans from around the world, Cameron is said to be developing a sequel.

However, according to star Sam Worthington, the decision for a follow-up won't be made fiscally, but instead by the overall acceptance of the movie.

"The deal is that the fact that people have embraced it means that Jimmy [Cameron] is seriously thinking about it," Worthington said. "He just has to find the challenge and that's the thing. He doesnt just dive in and do a movie 'cause the studio says he has to. That's Jim's spies coming in the window now so I can't say too much. It's all secret, hush hush."

Where will a sequel go now that the Na'vi have control over Pandora? No one is letting anything slip, but Worthington does have a few ideas of his own on what should happen next.

"Jake Sully, I'd like him to be ... I've always joked that he - the avatar - should get really fat," Worthington said. "And then Neytiri should come through the window and shoot him with an arrow and say, 'Come on, man up. Pull your weight a bit.' We have discussed where it could go, the possibilities of where the story could go. And in science-fiction, anything can happen."

An extended IMAX edition is already in the works with added scenes that were removed from the movie for the cinematic run. And, just as before, Cameron will hit another technological roadblock to seeing his vision completed. There is apparently more than 40 minutes' worth of footage that can be included in the updated release. Jowever the reel in IMAX theaters already was 170 minutes, meaning that Cameron can only add about another 10 minutes' worth of footage.

Should he choose to add all 40 minutes, then the updated cut is unlikely to be seen in IMAX.