Broadcast-live-video-from-desktop business is getting crowded.
Ustream is the last company launching a new desktop client. It is called Ustream Producer, and it includes high-video quality and editing tools to for live streams.
We are not talking about broadcasting via your web browser, using Flash to access your PC's webcam. We are talking about more complex broadcasts than a single stream. You can have simultaneously two streams or more.
With a desktop client like Ustream Producer (see picture below) you can stream in HD and H.264.