According to an article from the website, TVshowsonDVD back in August:
In a response to a question about TNG on Blu-ray, CBS Consumer Products VP John Van Citters told the convention crowd in Las Vegas that releasing Star Trek: The Next Generation on Blu-ray was much more "problematic" than the original Star Trek, due to how the TNG original effects shots were composited, and how that makes the transfer to HD "incredibly difficult without making them look awful." However, he also said that there is "a lot of conversations going on" within CBS on how to convert TNG to HD, and Van Citters expressed optimism noting "It is being worked on and I expect it will happen, it is just a technical challenge."
Following his talk, I confirmed with Van Citters that even though he is optimistic that the challenges will be met, as of now there is no specific plan or budget for the project within CBS. So this is still something that is a long-term project.
Taken from: http://www.tvshowsondvd.com/news/Sta...#ixzz13dHZmzCj