If you weren't content with just seeing Avatar in 3D in theaters, don't worry. According to James Cameron, we'll be seeing a 3D Blu-Ray version of the movie before the end of this year:
We'll do the Blu-ray and the standard def DVD April 22nd, that's our plan as of right now, and that'll be pretty much bare bones. And then we'll do a value-added DVD and a 3-D Blu-ray in I think November sometime.
Update: Sad news, folks; Fox dropped us a line to say that "3D is in the conceptual stage and Avatar will not be out on 3D Blu-ray in November."