Joost have just lost/pushed their CTO, Dirk-Willem van Gulik. He's jumped over (or been snapped up by) to the BBC to work on a range of back-end infrastructure to support their interactive services.
Joost, with its required client-side install, and funky UI, and un-compelling content has never seemed to have caught the masses attention. I have it, I played with it, I don't use it. With my various other video options (YouTube (& variants), AppleTV, OnDemand via cable, BBC iPlayer, etc.) it wont get my attention. Rumours imply their money is running out fast too.