Avatar tells a kind of neo-Pocahontas story of the 22nd Century United States' attempt to colonize Pandora, an outer space moon covered with blue tribal humanoids called the Na'vi. The character of Jake Scully (Sam Worthington) stands in for John Smith: a man sent out by his government to explore and learn about the people in order to benefit the colonizing effort. From the comfort of a high-tech tanning bed, Scully can remote control his "avatar," a sort of clone created by mixing human and alien DNA. Yet he soon discovers the value of Na'vi life, in all of its nature-connected splendor . . . And that he has the hots for Neytiri (Zoe Saldana), the daughter of the Na'vi clan leaders and stand-in for Pocahontas.
Other critics have equated it to a War on Terror-era comparison, which rings a little bit true when you consider the humans' "pre-emptive strike" strategy. Overall though, I think Pocahontas is a much stronger fit for juxtaposition. You've got the love story, the training of the white man to be more like the tribal people -- hell, even the sacred, talking (in a sense) tree.
As you've probably read and heard elsewhere, the visuals here are incredible. Normally I wouldn't say this about a movie, but it's worth catching for the CGI and special effects alone. And I didn't even see the 3-D or IMAX version. Cameron, who wrote and directed, has constructed a gorgeous glow-in-the-dark world out of scratch with its own interesting mythology. Considering the extent of the detail, it's hard to believe Avatar wasn't a New York Times bestselling book series first.
My only critiques are about the actors and character development. I wasn't very impressed by anyone's performance, and the straightforward plot structure didn't give the actors much wiggle room anyway. At the very least, you'd think maybe Cameron could have signed on Matt Damon in place of Worthington, but maybe the expenses were just too out-of-control for that. Either way, Avatar's beauty and creativity definitely outweigh its weaknesses.