I know it's a major and expensive undertaking but I would love to see Star Trek TNG, DS9, and VOY on blu-ray. As someone has already pointed out, since it was transfered to video and the effects were all done on video (as many shows from that era were), they would have to go back to the original film elements (if they even kept them), re-edit it each episode and re-do all the special effects in HD.
With the success of the new Star Trek movie, hopefully they'll feel the demand is there to give it a shot.
How many times do others need to say it? Movies and TV shows are NOT in the same shape a lot of the time. Virtually all major studio-backed feature films since feature filmmaking began have been shot on 35mm film or better, which has all the resolution HD needs and more. That's not always true of television. So-called one-camera shows like Bewitched definitely were, but anything shot on videotape before HD came along is doomed to remain in SD and there's little one can do about it. The 1926 version of "Ben-Hur" will look outstanding on Blu-Ray but "All in the Family" never will.
Shows that were shot on on film but edited on tape in the 80s and beyond would have to be re-edited from scratch using their 35mm source material if that material was kept. In these cases, unless the show in question is a "Seinfeld" or "Friends" there may be no financial incentive to progress to Blu-Ray.
There's also the question of special effects factors. During the remastering of Star Trek, many of the space ship scenes were re-done to fit the format. Releasing something on HD just isn't as easy as upconverting it from SD to HD and you're done. Upconverting introduces a TON of new issues that also need to be addressed. I know they're having trouble with converting Babylon 5 to HD since most of the CGI ship effects shots were video sourced but the CGI simply isn't of a high enough resolution to match any high-definition TV format and the HD upconvert is introducing some problems that are so severe, entire shots will need to be redone if there were to be a Blu-Ray DVD release. Also for some of the older shows it boils down to a Garbage In-Garbage Out situation and you can only use what source you got (in other words sometimes you can't polish a turd
However, people need to remember that we are only three years into the format, so expecting the same level of titles as we see on DVD this early is unrealistic. How long did it take before we saw a reasonable number of TV shows on DVD - and even with the market penetration DVD has, how many shows (or seasons in a lot of cases) aren't out on DVD?
We can expect recent shows that won't require a lot of work to be released, but older series are still a way off.