Had not heard this yet. It seems there was a logical conclusion to the first one though right?
Hold on let me check...wasn't there a straight to DVD sequal to Fern Gully? To me Avatar is one of the worse JC films of his career. Take away the special effects and the logic/story is stupid. Watched it all the way through, but it was tough.
I enjoyed Piranha two, the spawning (Flying Piranha for those who haven't seen it) more than Avatar. I didn't expect as much from a low-budget B-movie, but I kept watching....I expected so much more from Avatar.
My guess is that once filmmakers become too revered, too famous, they begin to believe that their sh*t doesn't stink and no one near them challenges them on their decisions. I.e George Lucas, Ridley Scott, etc....