We always knew that Avatar would spurn 2 sequels, and now it’s going to go again with a fourth movie. And it’ll all be back to back as well. Sigourney Weaver has been speaking saying she has no idea how long it will take or how its going to work and that she will just show up for work.
What James Cameron has in mind for 3 more Avatar movies is beyond me. It’s widely perceived that the second one will feature some oceanic shenanigans as for 3 and 4? Space is surely out of the question for the Na’Vi, so who knows. Whether or not the sequels can bring in as much cash as the original remains to be seen.