Google has released newly updated youtube app for its TV

A new YouTube updated app has been released by Google that may be downloaded freely from Android Market on Google TV 2.0 boxes.

From SayPeople,

The app is also introducing new feature called as “Discover” for filtering YouTube channels by categories consisting of comedy, science, cooking, gaming and such other categories. Each channel gives easier access to playlists and individual videos. There is also a “From TV” option showing broadcasted channels.
Users can also subscribe to channels with a single click. Users may scroll through related videos or other videos by the same user while pressing up or down arrows on the remote control.

Further Reading:
SayPeople