Director James Cameron's plan to revisit Pandora is taking a Star Wars-esque route, as the Avatar director announced the fourth film in the series will be a prequel, taking place 35 years before the events of the first film.
In an interview with MTV, Cameron said he hasn't put pen to paper, but has an idea of what the prequel will address:
...basically it goes back to the early expeditions of Pandora, and kind of what went wrong with the humans and the Na'vi and what that was like to be an explorer and living in that world.
Whether it leads to more prequels is dependent on the the story-telling process:
...it's a logical thing to do because we'll have completed the thematic arc by the end of three. The only thing left to do is go back to see what it was like on those first expeditions and create some new characters that then become legacy characters in later films. It's a plan.