I've wanted this for a while, but I don't think it will be coming soon. Reason being, is in one of the latest Zune Insider podcasts, @Jetherealz filled us in on how the Zune Pass works exactly. It works like a radio station when paying royalties to the artists. Every time a radio station plays a song, they owe so much to the artist. So every time someone downloads a song, Zune owes so much to the artist. Not the full price of the song, because they're not actually selling it, but some royalty must be paid. Seeing how television doesn't work at all like this, I don't see this happening. It could I guess, but I don't think the television companies would be willing to do something like this.
http://themookoojoe.wordpress.com