I don't know if many people know this, but I am afraid they don't.
LAUNCH is a music video/entertainem portal on the Yahoo platform. You can get access to the latest music-vids there, have a lot of cool radio stations to tune in and stuff. I really like it although I must admit that I got registered there about 3 years ago long before Yahoo had a part in the portal. Since then performance and reach have decreased a little in my opinion but maybe that is only due to the public exposure.

Anyhow if you were looking for a place to stream your favorite music vids from. Launch is the place to go for you.