Even if they do re-release TNG on bluray, I am not going to buy it. I have all the trek series on standard DVD, and I dropped some coin for that. And you know what, it looks fine in an up scaling dvd player. Yeah, its annoying that I don't get a full screen, but it really isn't that big a deal to me. I have a 42" screen, and even in the standard format, it's big enough.
Ugh, I went through this already, when I upgraded from VHS to DVD.
I am not going to re-buy episodes I already have (some of which I have already seen 10+ times), just so I can see them in bluray.
The only thing I would consider re-buying on bluray, is the feature films.