Let me try and score this here, "Moofie."
So, it's all you want in a bad ass, futuristic, alien fighting shoot'em up. However, it lacks so fucking much in plot that anyone with cinematic taste may get up and leave. The 3D will blow you away the first time; it's really the best looking shit I've seen in my life.
However, remember that James Cameron spent his whole damn career making the movie. It should be much better.
8/10 tops. And because I'm a sucker for the big fights.