Now that Steam's in-home streaming is out of beta

I'd enjoy a video on a minimum build for Steam in-home streaming.

I know the requirements for the receiving machine are low, but just how low can you go?

Assuming you use the Steam OS, what's a good minimum build that can run the OS, handle the networking, video decoding, and has good wireless controller support?

I'm sure there are minimum specs listed but it  think I'd be really cool to be able to have a steam app for the new consoles or even the older last Gen consoles to play nice games off your pc to your console. But that would probably never happen. I have an old Xbox 360, or rather one working and three RROD ones but I'd be cool to put my working one in the living room. Ah, pipe dreams.