An update to the beta version of the Steam client adds an early look at the computer-to-computer streaming that will be an integral part of Valve's SteamOS and Steam Machines. The option for in-home streaming, which requires some "tinkering" to access, according to the unofficial Steam Database, doesn't appear to function yet for users, but offers some insight into Valve's plans.
In-home streaming options, shown in screen caps from the beta Steam client, indicate that multiple streaming source computers can be set up on a local network. Steam users will have the option to limit the bandwidth and framerate on a stream to improve its performance, and users will be able to browse streaming sources in Big Picture mode.
One of the major obstacles in getting the beta version of in-home streaming working is the inability to simultaneously log into a Steam account on multiple devices to authorize the feature. Steam DB theorizes that this option will be added by the time the Steam Machines beta rolls out to 300 select users later this year.
In-home streaming will be a key component of SteamOS when Valve launches the Linux-based operating system and associated hardware next year. Valve plans to make the broad Steam library available to users of SteamOS by streaming content — including games, music and movies — from Windows and Mac PCs.