Is it possible that the original live-action green/bluescreen base video assets for Myst exist in some form? (i.e. a lost camera videotape, Hi-8, etc.)
If they did exist, and it was possible to use them, they could probably be used to create an "upgraded" version of the game (possibly for the mystery version we've seen on Twitter!). Sure, the background animation or graphics wouldn't be the same, but it would certainly be better than the quality of the converted videos seen in realMyst! It would be a blast from the past, with a breath of fresh air from the "future"!