I talked a few times about a peer to peer video sharing system which is a bit like joost but most for user than as joost done ( centralize film where p2p is only here to descrease the use of server bandwich).
And I think to something quite similare as Democracy done. Democracy is a peer to peer video sharing system which have a GUI done with XUL ( as joost) and use VLC to read video. With that you can read quite all video of web 😉
You can read a short describtive of Democracy in french here.
Every viewer can been author and done is own channel. It take the same concept of web 2.0 (a video wiki).
I am more and more thinking to done something quite similare with mono/monotorrent lib and maybe something as XUL or moonlight for IHM. Just for pleasure of discover a real ammazing system.