YouTube Paid Channels And Apple TV.
As I write this, the Apple TV YouTube interface (app?) does not support the YouTube Paid Channels program. You can see a channel you've subscribe to in your list of channels but it doesn't pull up any of the videos.
I don't know if we'll see an update any time soon (as is does compete with what Apple TV is trying to do), but if you watch this video:
The Paid Channels work great in either the iPhone or iPad YouTube App and they do Airplay quite nicely.