Just when Joost gave up the desktop client, I was directed to another streaming video client that really works: Livestation.
Livestation uses a peer to peer protocol to stream video around and presumably avoids the scaling problems and high bandwidth costs that plague one to many schemes.
Although there's lots of stations listed, many don't work for me here in Australia, perhaps due to some sort of geographic filtering.
Here's what works for me: BBC World News, Sky News, Al Jazeera in English, C-SPAN, France 24, ITN, NASA TV, Russia Today, FOX 11 LA.
I'd like to watch a bit of CNN but although it's listed all over the place none of them work for me.
It seems like users can contribute their own streams, and for me they never work. I can see on the site that some providers are in their requesting that their user streams are removed.
The client is available for Windows, Mac and Linux, it's a QT portable application and right now it's ugly.