I give this movie an A-minus. What was wrong with it? The villain was completely one-dimensional, with no motivation except simple war-mongering. All the characters could have used more detail and emotion. Also, the plot is completely cribbed from Disney's screenplay for Pocahontas, so I never for one moment wondered what would happen next.
It is not necessary to see Avatar in 3D. It was only occasionally distracting. If you have not yet seen a movie with this new 3D technology, picture and entire movie presented like a ViewMaster, and that's the sensation you get. (In REALD 3D at Cinema Du Lux, Dedham)