in the case of the StarTrek HD, they are actually remastered and have added new CGI effects to replace some of the old poor special effect shots.
other shows, probably only go through hardware upscaling and anti-aliasing.
Hopefullly good ones.
remember, there are technically 13 specifications for HD. but now we are down to about 6-7 in practicality. and only 3-4 of any real meaning as far as support goes