I suspect the early speculation that Avatar2 will be about the Pandoran Undersea people is a tactical diversion. And while I don't necessarily believe there's an ophan planet NIBIRU on its way back into our Solar System in 2012, Avatar2 will most likely be about this symbolic RETURN OF THE ANNUNAKI to the dead (corporate) earth. It'll show how the remaining 'humans' on Pandora negotiated 'unobtainium' refinement and 'tree of souls' crystalline glimmering poperties in the name of a pre-emptive strike on a poisoned earth and a broken humanity, led by Jake Sully's Cain & Abel offspring. Imagine Tree of Souls SPACESHIPS flown by the spiritual elders and powered by hearts of purified 'unobtainium'.
I can picture the opening scenes now, a blue foot steps lightly off a glowing Federation of Light Ship. Pan up to Jake Sully junior, his full tribal regalia lifting in the anti-grav field, towering over the assembled corporate heads of what has become a City Planet like Star Wars' Coruscant ready to beg for their lives. And all the gullible Project Bluebeam idiots will suck it up like puppies at the teat, the weakness of humanity used against itself. People will LITERALLY try to worship these Blue Magicians sent back from times gone by to fix the Earth and liberate its people from Corporate Indenture.
The returned 'prodigal' son of Jake Sully will FLOAT instead of walking due to his 'unobtainium' belt. Imagine that Blue Angel moving through the conrete jungle levelling all in its wake and nullifying all mankind's Corporate War Weaponry. In fact, this refinement of 'unobtainium' and 'tree of souls' housing will probably allow mankind to agree to BANISH ITSELF from the surface of Dead Earth for ONE HUNDRED YEARS (this being the minimum amount of time needed to undo the damage done by millennia of Empire structure) so that hybrid seeds from Pandora can be sown into the un-concreted soil to help rebuild a connected network of organic-relevant existence on this planet.