I suspect there won't be a sequel. Not unless the Na'vi can come up with a strategic weapon that can be used as a deterrent to a retaliatory strike. Maybe unobtanium has some as yet unknown properties that might help them.

It had to be a pretty simple story line, so that the propaganda would be easily assimilated. I like the dig at the end about how earth had destroyed it's own eco-system, and would be happy to destroy this one as well.

Entertaining, but obvious.