James Cameron was recently quoted as saying the following:
“I’m working on Avatar 2 and Avatar 3. I was talking the other day with Peter Jackson and said, ‘You had it easy dude. You had the books when you did the second and third ‘Lord of the Rings.’ I have to create my own books in my head and extract a script from it. I’m deep into it and I’m living in Pandora right now. There is that start up torque where you feel it’s coming to you. Then you build up momentum. That’s when it gets fun. The characters talk and it’s writing itself. I’m almost there right now. It’s building fast.”
I’m not sure why it’s taking so long. He must not know that there was a Ferngully 2.