Valve's 'Steam Box' Breaks Cover at CES with Xi3's Piston PC
A company called Xi3 showed up with a modular computer codenamed "Piston," which Valve and Xi3 confirmed is a "computer game system optimized for Steam gameplay." In other words, this is the Steam Box we've been hearing so much about, Polygon reports.
Image Source: Polygon

Image Source: Polygon
Some additional details are available by spying shots of the Piston. You can clearly see, for example, an Ethernet port, audio in/outputs, SPDIF optical audio, four SuperSpeed USB 3.0 ports, four USB 2.0 ports, four eSATA ports, two mini-DisplayPorts, and one combo DisplayPort/HDMI port.

Image Source: Polygon
The Steam Box (or whatever it actually ends up being called) will take advantage of Valve's Big Picture mode, which is a special interface designed for HDTVs rather than PC monitors.
There are still many questions left unanswered, and they're not just about the hardware. Will the Steam Box run Windows or Linux? How much will it cost? When will it be available to purchase? Answers to these questions are unknown at this time.