There are two things you have to look at that allows you to sell copies of the South Park Xmas episode.
1) If someone sends you money for a copy of the tape and pays for the shipping and handling then its ok.
2) No where on the Xmas episode, which I've seen via RealAudio is there anywhere located that Comedy Central owns copyright of this. Just cause they show the new episodes doesnt mean they have the right to this episode until they show it and use it under their credits. This happens everyday in our world and under different circumstances. Its like if you sell a game which some company owns to someone else, it doesnt mean anything. You can look at this in many ways but take it as you want.
I am also looking for the Xmas episode on VHS. I am willing to pay for the tape and/or shipping and handling. Email me if you want to talk.
Gumbo ... Wasted Youth Inc. [email]
The Realmz Of Gumbo ... http://www.mindspring.com/~obmug