Right now 3D is "faked" it's done with two cameras right next to eachother each "polarized" differently to give the viewe with the glasses each view seperately (or at once.) For example, in Avatar's 3D one camera recorded a certain wavelength of video from its prespective and the other camera the another. These two are played at the same time and picked up seprately by the glasses translating to your brain as a "3D" image. But it's faked. It's no more 3D than, say, colorforms as the prespective on the screen doesn't change based on where the viewer sits. It's all from the "camera's" POV. If it was truely 3D you could move more to the right and see more of what's behind the guy in center frame. The presepctive and view would change from the watcher's POV. This kind of 3D is likely possible, even without glasses, but a long-way away.
The new 3D TVs work by recording the two images at once but also displaying them both at once. The glasses are part of technology by shutting one eye off and the other eye on several times a second to give a 3D-like effect. But, again, this is a "fake" 3D that gives an illusion of depth.
But the 3D used for movies has one critical component: Two side-by-side cameras. One for each of the viewer's eye. For TNG it was recoded with only one camera doing the shot. Not two side-by-side cameras.
For this to be 3D someone has, essentialy, go in with a computer, cut out all of the foreground stuff, fill in the background stuff and then make a second camera in the computer. Done "right" the effect can be good but it's more likely to look like colorforms (foreground images being placed on the screen ontop of the background) than it is any illusion of reality and depth.
This is what would have to be done to make TNG 3D. Every single frame of film -because again all of the episodes would have to be re-edited from the original film as the episodes were edited on videotape and wouldn't have sufficent resolution for HDTVs- would have to be cut into two pieces. The "foreground" and the "background." The missing background (where the foreground stuff was) would have to be filled in with CGI or other shots, then the foreground stuff would have to be-re-edited back in. Again, this would have to be done for every. Single. Frame. Of the episodes! That's 26 frames a minute for 40-some minute long episodes.
Done right, this can be a good effect but requires a lot of good, talented, CGI to make the backgrounds match the filled-in-stuff and to even give the "foreground" stuff more depth (again, to avoid the "colorform" effect.) I simply do not see how this would feasable for a 20 year old TV show that's already got a shit-tone of work that needs to be done on it to just make it viable on BD in 2D!
This is one of the problems with these new 3D TVs. They won't make everything you play on them 3D. The stuff has to of been filmed in 3D, and then released in 3D. It won't make anything played on it 3D. So, for example, you'll never see a "Ghostbusters in 3D" because Ghostbusters was never filmed in 3D. To make it 3D it'd have to be "faked" using CGI.
I believe there's some primitive glasses-less 3D technologies in the works out there. One idea I think could work is having several layers of transparent TV screens eachone displaying something slightly different and each one being a "cube" capable of showing an image on its face and side. The result being a "true" 3D image with a prespective that changes from the viewing angle.
Something like this:
The pixels being opacity being adjustable depending on what's supposed to be there, or guess just opaque when activated and being transparent when "off", that is when representing dead space/air. I'm thinking of something like 100s or 1000s of layers to give a real "depth resolution" and I think with the right prespectives a good sense of depth could be simulated.
