What has been hinted at more than a year ago (and a couple of more times since then) is now official: 20th Century Fox and James Cameron announced today that there will be three Avatar sequels. The first will be released in December 2016. The other two will follow one year later, respectively. All three films will be shot simultaneously.
Now the actual news: James Cameron has hired four screenwriters to get the three screenplays done. Josh Friedman (War of the Worlds) will write one of the films, Rick Jaffa & Amanda Silver (Rise of the Planets of the Apes) a second and Shane Salerno (Savages, Armageddon) a third.
James Cameron and Jon Landau will be the producers. Joe Letteri and Weta Digital are responsible for creating the world visually.
20th Century Fox CEO Jim Gianopulos must be very convinced of James Cameron's plans for the sequels. Apparently, Cameron was supposed to direct a film called Cleopatra featuring Angelina Jolie, which he was pulled out of by Gianopulos so that he can focus on Avatar. Gianopulos said: “We at the studio have no higher priority, and can feel no greater joy, than enabling Jim to continue and expand his vision of the world of Avatar. The growing breadth and scale of Jim Cameron’s plans for his magnificent fantasy worlds continue to amaze us all.”
For those who are interested in the technical aspects: Last week, Jon Landau was at SIGGRAPH in Anaheim, a conference on computer graphics. He presented a series of clips of test footage that was shot last November and features a human and a Na'vi. They use Autodesk Motion Builder for improvements in lighting and shadows with the goal to send more detailed imagery to WETA to work with, making the overall process more efficient. James Cameron's ultimate goal is to be able to light and shadow the virtual sets on stage in realtime to get a better idea of the final scene and improve the storytelling.
Sources:
http://www.deadline.com/2013/08/fox-james-cameron-set-group-of-writers-to-spearhead-trio-of-avatar-sequels/
http://www.hollywoodreporter.com/behind-screen/siggraph-avatar-2-producer-jon-592409