Putting TNG on blu-ray is inevitable. Star Trek is still one of the most popular and well-known franchises ever made, and there's lots of money to be had here.
Of course, but is there *enough* money to justify the massive amounts of work? It would take a lot longer than TOS-R did (I'm guessing at least 5 years, and that's assuming that they can farm out the work to multiple outlets so as to work on many episodes at once), and also the actual amount of work would be much greater. The ROI may not be enough.
I can definitely see a HD 'fan collective' or two, but not necessarily the entire series.
I think that Enterprise
will be the next Trek series to make it to Blu-Ray. There's fewer episodes, and they're closer to HD-ready (the show has even aired in native HD).