Valve and Xi3 announced to the world that a Steam Box is on the way and will be shown at CES this week. Now, the two have shown off the Piston, one of several Steam Box prototypes at CES. The Piston is based on Xi3's X7A series, and more specifically the performance option that starts at $999. Neither Valve nor Xi3 are discussing the price of the Piston, but I'd have to imagine it'd be considerably less in order to compete with consoles. An entry-level version, the X5A, starts at $499 and runs on Linux, so that could be a potential stepping stone for the Steam Box. The hardware difference between the Piston and X7A was also not discussed, except for Xi3's chief marketing officer, David Politis, saying it'll have up to 1TB of storage and feature the company's modular components. Users will be able to upgrade the CPU and RAM for sure, and it's possible the CPU upgrade will also affect the GPU if something like an AMD A-Series APU is used.
Connectivity options on the Piston are pretty vast, as the prototype features an Ethernet port, audio in/out, S/PDIF out, four USB 3.0 ports, four USB 2.0 ports with one dedicated solely for keyboards, four eSATAp (eSATA/USB combo) ports, two Mini DisplayPorts, and one DisplayPort/HDMI combo port. Valve has multiple prototypes and some "off-the-shelf PCs" at CES for demonstrations, with the prototypes described by Valve's marketing director, Dave Lombardi, as "low-cost, high-performance designs for the living room that are great candidates for Steam and Big Picture." All of this is potentially big news, so just keep it tuned for more updates.