CapNews.net describes itself this way:

CapNews.Net is an Internet News Service covering Congress, the White House, the Supreme Court and executive agencies.... In 2008 CapNews.Net will launch its full operations and begin offering news video syndication services to media organizations and others, and also continue posting videos directly to the public via YouTube.com and other video platforms.

You can find their YouTube videos here and others on Google Video here. I haven't discovered any comprehensive list or index or indication of what their coverage is or will be, but this looks like a service that could develop into a key resource for fast access to Congressional hearings. See for example The Cyber Initiative hearings, Committee on Homeland Security, Thursday, February 28, 2008. A version is also available on the committee's website, here.