Re 3D: The only reason we pay the extra money for 3D is that the 2D is not available at the time we want. I think 3D is a clear example of technology for its own sake (ooh! cool!), but which doesn't actually help the story be experienced (your involvement with the characters is not enhanced at all, etc).
The picture should be just as bright for a 3d projection. Unfortunately, that means a more expensive light source (or two separate ones). The decision to simply use an old lamp at half intensity may have made immediate cost-cutting sense, but it's damaging the 3D brand. Case in point, Tron 2 3D was dim to the point that I removed the polarizers for the 2d-only scenes. The difference is quite visible.
There was a piece posted here some months ago that made the claim that 3D movies would never work, because the human eye (or brain) has to work harder than normal to process the false perception of near and far objects which the eye has to focus on at one fixed distance (the screen surface).
