Note that Avatar was created in 3D using 3D cameras and 3D CGI techniques.

The method proposed here and used in many of the current crop of 3D films is using a conversion technique to convert a 2D film to 3D (though the 2D film may have scenes deliberately shot in a style that best suits the 3D conversion process).

The result will not be like Avatar and to get good effect they may have to resort to "in your face" shots. It's a cheap gimmick basically.

Oh, and at home, unless you buy one of the new 3D HDTVs that are coming out (very expensive), you will be using the old red/blue(or green) glasses as used in the 50s which is nauseating and limits the colour depth and resolution. It's a compromise. True 3D TVs work as in the current 3D cinemas, using polarised display and glasses.

Leave them alone I say, or shoot properly in 3D. But as the rest of the series was not shot in 3D it seems pointless.