To me 3D is cool as long as the movie don't throw things to the face of the audience every 2 minutes (unless it's a ride of course)

Bad thing about old 3D was that the effects were way to over the top, resulting headaches.

I heard Cameron said that a simple 3D scene with two people walking in a garden with the snow falling could be a good use of 3D cause in that case the effect would help the mood of the scene and would not be just an "in your face" effect.

I think 3D could be a good tool in the right hands. About turning 2D movies in 3D... I don't know. As long as it's just for the fun of it, why not.

All in all I think we are still taken out of the movie by the 3D because we are not very used to it yet. I don't want 3D to take over 2D, but I'm not against it.