From Yahoo! News:
By now everyone knows that not only is "Avatar" a huge hit, but also director James Cameron never expected it to be anything less than a blockbuster. So it's not a huge surprise that the director confirms this week that he has always planned to do an "Avatar" sequel, and hopefully even turn the franchise into a trilogy (you hear that, George Lucas?).
"I've had a storyline in mind from the start - there are even scenes in 'Avatar' that I kept in because they lead to the sequel," Cameron tells Entertainment Weekly in this week's issue. "It just makes sense to think of it as a two or three film arc, in terms of the business plan. 'The CG [computer graphic] plants and trees and creatures and the musculo-skeletal rigging of the main characters - that all takes an enormous amount of time to create. It'd be a waste not to use it again."
In other words: Cameron is taking a kind of "green" approach to the blue-skinned characters: Recycle, reuse, and reduce what might otherwise be underused filmmaking.
Read full article: http://movies.yahoo.com/feature/movie-talk-avatar-trilogy.html