While it didn't make AFI's Top Ten Films of 2009, James Cameron's Avatar was singled out in a different way. The institution named the release of the film as one of 2009's Most Significant Moments.
"With an army of technological wizards at his side, writer/director/producer/co-editor Cameron called upon the forces of art and technology to create new tools for storytelling that are groundbreaking in both scope and scale. The magic of the motion picture -- and the transfer of its power to television and now video games -- has always found its truest power in its immersive qualities, and with Cameron's advances in CGI and 3-D, 'Avatar' enters AFI's almanac as an achievement that will have profound effects on the future of the art form." That's AFI's fancy way of saying, yeah, Avatar is a game-changer.
I think part of the "game changer" status isn't up for adult fans and critics to decide anyway. Like Star Wars and Jurassic Park, the generation of children that Avatar impacts will be the ones that determine if it changed the game. These are the audience members who might take their experience with Avatar and attempt to find new ways to make a similar connection with future audiences, in regards to inventing new technology to more fully unleash their imaginations.