I'm gonna watch it today (in about 5 hours' time), in 3D.
I'm not sure what to expect... One thing I can be sure about even without reading your comments (which I did) is that yes, for the most part the plot is a cliché, and by reading your comments, I can guess that all of it is...
but the thing is, I'll be pretty satisfied with the effects, a mediocre plot and, of cource, 3D.... or I better be, that is, it costs like 1,5 times the cost of a normal movie.
There is one thing I can't quite get though. Even the miner folks being capitalists with a capital, underlined italic C, I don't see how on earth they could justify killing a whole race for a mineral or something... I'll just have to see.