What is Valve's Steam Box?
Steam Box is Valve-developed hardware that has yet to be unveiled. According to Valve co-founder Gabe Newell the Steam Box will be distributed entirely by Valve.
Why is Valve Making a Steam Box?
Valve has a very successful digital distribution platform with Steam and has become extremely interested in expanding its reach. The Big Picture mode is part of the process, which gives Steam a facelift and makes it more gamepad-friendly for use on a big TV in the living room. The Steam Box is the next step, merging interface with hardware and, at least in theory, letting Valve reach customers who'd normally be scared of more traditional PC gaming.
How is Steam Box Different from a Standard PC?
That's not clear yet. It may just be a small form factor PC. It will, according to Newell, be Linux-based. It will not be a closed system like a console. Newell mentioned it will be entirely possible to install Windows on the Steam Box.
How Much Will a Steam Box Cost?
This is not yet known. It all depends on which components Valve decides to offer as well as what the input device turns out to be.
Will the Steam Box Have a Unique Input Device?
Newell has indicated that there will be a unique input device for the Steam Box that could somehow utilize biometrics and gaze tracking. He is not very fond of Wii-like or Kinect-like motion controls. Valve in the past has also backed the Oculus Rift, a virtual reality device, and expressed interest in the possibilities of augmented reality gaming.
What Special Features will the Steam Box Have?
Valve seems very interested in the idea of using one Steam Box to send a signal to numerous monitors through local networks, perhaps as much as eight, so that one Steam Box could serve an entire household.
Is Xi3's Piston the Steam Box?
Sort of. It is not made by Valve, though it is associated with Valve. Some companies, like Xi3 with Piston and NVIDIA with Project Shield, are working with Valve in some capacity. In some cases, like with Xi3, Valve has even directly invested in other companies. This is likely to help the companies produce hardware that might be appealing to a more general audience and then only talk about Steam games, as opposed to PC games. Valve has said we should expect more announcements from other companies about different styles of gaming machines throughout 2013, but those won't necessarily be the official, Valve-produced Steam Box.
More on the Xi3 Piston
More on Nvidia's Project Shield
So When is the Steam Box Going to be Ready?
Also unknown for now, though a recent interview with Valve engineer Ben Krasnow seems to indicate it may not be until 2014.