Rumours are that Valve has been working on a 'Steam Box' console for quite some time and may very well at last announce such a device at either this year's Game Developers Conference (GDC) or E3 events.
It has been suggested that Valve is looking to create an open platform for gaming not dissimilar to Sony's 'PlayStation Certified' approach for Android, though for the PC, whereby Valve provides a software platform including content delivery. Hardware manufacturers are to offer up systems that meet Valve's minimum specifications to ensure a common base for developers to work from, according to reports. This should ensure consumers looking to purchase their next computer will have greater compatibility with the latest games for the next three or so years.
It has even been suggested that Valve is working on its own official gaming peripheral specifications to help narrow down the diversity for developers and consumers. Apparently at this year's CES, a hand-built concept of the console was demonstrated behind closed doors, featuring an Intel Core i7 CPU, 8GB RAM and an NVIDIA GPU.
There are some interesting insights to be found at the following sources, though at this stage a 'Steam Box' is a speculative rumour; there are strong suggestions that something may indeed be stirring inside the walls of Valve HQ and we wonder if it has the potential to shake up the gaming industry; we also wonder just how, if at all, this will factor in with the expected next-gen Xbox and PlayStation offerings.
http://www.steampowered.com/steamworks/thebigpicture.php
http://www.gamesradar.com/valve-has-three-big-surprises-for-us-is-experimenting-with-biometrics/
http://www.faqs.org/patents/app/20110105231#b
Credit to TheVerge for piecing together all the facts.