It is possible to embed Live Video Streaming in Google Sites. There are several companies that allow you to broadcast Live and offer additional video services (ie. video editing , video archiving).
Other software companies have media streaming and broadcast software to help you create and monitor your streaming video.
As video streaming becomes increasingly popular , existing video services are starting to offer streaming services.
YouTube live streaming is being commercially pro-typed at the moment and may be available to the public mid 2011. Further Integration possibilities for Google apps and Google sites.