Remember that hand-sized PC called Piston made by Xi3 that was thought to be Valve's Steam Box?
The company name Infinity Ward is stamped on the side of the Piston PC. Underneath it is what looks like the even smaller Xi3 Z3ro Pro Computer.
Infinity Ward said nowt else.
Piston turned out not to be Valve's Steam Box but one of many Steam-affiliated PCs in development. Infinity Ward owning one that has its name on the side suggests whatever Infinity Ward is making - Modern Warfare 4, presumably - will be optimised for it.
Xi3's computers are built differently to normal PCs. The Piston's titchy form factor comes from unique architecture that splits the PC into three parts, each of which can be swapped and upgraded for newer Xi3-made parts as and when they're released.
Maybe there will even be a Modern Warfare 4 Piston bundle sold this autumn when the as yet unannounced new Call of Duty game will presumably be released.
Whatever the details of the partnership are, it's a statement of intent by Infinity Ward - one of the world's most successful developers - that it's taking Xi3's computers seriously.
The Xi3 website hasn't any extra information about Piston. But the product page for the X7A Modula computer - the PC that Piston is built to be like - has detailed and relevant information.
Valve's actual Steam Box hasn't been seen. Gabe Newell said it will be a Linux box and that Valve will sell it to people itself. Maybe it'll even come with a weird-maybe-brilliant controller that has biometric sensors. Maybe it will come with clippings of Gabe Newell's beard.