The European broadcasting body is looking into a file sharing system called Tribler for distributing HDTV content. Tribler is different to other systems such as those used by BBC iPlayer and 4oD in that it runs on a credit system. Credits are earned by sharing material with others, thus encouraging more people to leave devices on to share material. More on this story over at BBC News Online.
Interestingly the PlayStation 3 has been made to run Tribler turning the gaming console into a video-sharing device. Enabling TV downloads on a wide range of devices is key to ensuring widespread adoption of the services.
While peer to peer techniques make the service delivery cheap for the content provider, it is not really saving money in general. The cost is moved to someone else which is either the broadband provider, if they run an unlimited service, or the consumer. One other hidden cost is the electricity for keeping a device on long enough to download content, which if downloading from other broadband users, can take a long time.