[quote name='meager']I'm no expert, of course, I was using information obtained from watching a commentary from some restored movie on dvd (I don't remember which, but it was a 60s movie) where the restoration crew was talking about what they had to do to remaster the print from the poor negative. Perhaps it is the film stock that the substandard part? I know they said they had to fake the audio seperation due to the lack of technology when the movie was made.[/quote]
Obviously, some films will have been preserved better than others, and in almost every case, some restoration work will be done, even with well-preserved stock. But the source material itself is, as I said, infinite in resolution, so it's worth the effort.
And for the record, colorization (which was introduced in the 80s and done with computers, and was in no way associated with the transition to color TV or color film, which happened long before) is not an accurate comparison, since it involves altering and essentially bastardizing the original B&W print to achieve something the original filmmakers never intended. Thankfully, they pretty much abandoned that process almost as soon as they invented it.
Sound is a different matter. Most films up until the late 80s were in mono or stereo, with some exceptions. If they can get their hands on the original audio tracks, they will often do a surround remix (but in many cases will also offer the original mix for the sake of authenticity).
So if film is HD-able, does that mean TV shows not shot on film are out of the running for BluRay?
No. It just means they won't look as good and will probably be among the last to get a BluRay release. You can only do so much with video tape.