g4tv.com has a special browser for the wii. If you watch the channel you will know what's on there because it's basically like a youtube for G4TV, but for people who haven't been to the site and don't watch the tv channel there is...
X-Play: Video reviews for new games.
Cheat: A show where they walk you through certain unlockables and hidden items in games.
Attack of the Show: It's basically a news show for all things tech and games
They have other things but I don't think it's anything worth mentioning.