Since I guess Chino would know the most about this, what is Cameron even planning on doing with Avatar sequels? I can't possibly imagine a new storyline that would warrant a movie aside from just being purely a money grab.
Well Cameron has said that we are going to get to dive deep into the oceans of Pandora. Probably seeing all new creatures and underwater worlds just as awesome as the stuff on land. We will probably get more insight as to the state of the Earth, and why our presence on Pandora is so crucial for mankind's survival. I'll guarantee that Hells' Gate is not the only base on Pandora. There is probably another RDA facility near by, that will once again be out for redemption. As for the 3rd movie, I have no clue. I would be willing to bet it ends with Jake knocking Neytiri up.
On a side note, anyone plan on getting the collectors edition? I already have mine reserved.