I’m a beta tester and I can’t say I’m terribly impressed. At least, with the video selection. The video quality is vastly improved over YouTube and such sites. Freepmail me how to send invites.
What is it exactly? Like MobiTV, but with chat capabilities?
Channel lineup will expand over time. They've already signed a deal with CBS. If you look at the major networks, they're already distributing a lot of their TV shows online on their own sites. But the Joost architecture will be a much better delivery system (think torrent-like P2P for streaming video). It is the future of video broadcasting and distribution. In 10 years people will wonder how anyone ever accepted having to catch a show (to watch or record) only when it was broadcast live. Tivo is one way of solving this problem, but it requires you to have a separate cable or satellite TV service.