This great feature comes in the form of a plugin for the main app. As long as you have a jailbroken PS3 and the homebrew app Showtime, soon you'll be kicking back watching your favorite shows on your gaming console. To be sure your favorite channel is added, shoot off an email to email@example.com, and it may well make the final release.
EDIT: facanferff, the developer of this plugin has commented here on PSX-Scene to verify some information for us.
There is a short list of channels already supported, but it seems it is growing quick enough to be updated daily. Here is the most recent list: