Buzz is about concerning a potential game machine from Valve. If rumours hold true then be sure to expect it sometime around 2109.
Aside from the infamous "Valve Time" the company seems to do pretty well for itself; their games are usually received quite well and meet with a lot of acclaim, and Steam seems to be proof that shockingly if you actually don't jerk around your customer base that they'll in turn love you for it. With the various degrees of success what could be next for Gabe n' company? The answer might be a bid to throw in the pot to the console wars.
Coming from this article featured in The Verge there seem to be hints of ... something stirring within the walls at Valve. If the rumours hold true -- which as I must emphasize is anyone's best guess at this point -- then this "Steam Box" might be shown as early as the Game Developers Conference, which is actually underway as you read this post. If not at the GDC then perhaps at E3.
Potentials for this console/computer mash-up include potentially customizable controllers, the ability to upgrade the hardware inside the system as it becomes necessary, and a more open platform in terms of development for both games and applications for the system.
Although the article states that Valve seems to be more interested in competing with Apple than Sony, Nintendo, or Microsoft, there's little doubt that the big three might see this as a potential new kid on the block. That could pose a decent problem, especially since it might seem poised to compete against the big three at the worst possible time for them: the transition from the seventh to eighth generation of their home systems.
Of course questions to arise from this: will this system be closer to a console or a computer? If the latter is the case then what might Valve plan to draw the gaming crowd from the PC to use something that for them may not be as convenient. Distribution methods are also a large question; Steam mostly lives off of users downloading games they want directly, while consoles still tend to rely in large part on the issuing of physical copies of games. If Valve does decide to go digital only they could find themselves alienating users that don't have high speed internet access or prefer physical mediums for their games.
Of course, all of this is mere speculation at this point, but if even the basis of this holds true and Valve is planning something then the console wars might have just gotten a hell of a lot more complicated, and interesting.