The Opera browser for the Wii is already getting raves from users for its visual similarity to Wii Channels. The six-window arrangement makes it easy to find videos of interest, and when you blow up a video to perfectly fit a full-screen, it correctly behaves like a regular desktop browser. The regular internet Wii browser sometimes forced full-screen videos of the TV screen, which was annoying. I tried the channel earlier today and browsing through videos was simple and intuitive, just like the site. You do lose some functionality from the regular browser, but it look great.
According to the respective companies, there are currently about 40 million Wii owners worldwide and over 20 million PS3 owners. The intent of both channels is to offer an easy-to-use interface for full size screens. Now, the only big-time system without a dedicated YouTube channel is the Xbox 360. Also even Xbox subscription has dropped, still its not free.