After a three-day countdown on the Steam page, the clock finally ticked over and Valve revealed their Steam OS, a free operating system (based on Linux) for playing (some) Steam games, and streaming ones that don’t work with it properly. In-home Streaming lets you play your Windows (or Mac) games via a SteamOS PC, by streaming the gameplay from your PC to another PC that’s hooked up to your TV. Because for some reason that’s a thing these days, having a “media PC” that sits next to your TV and acts as a movie/music server. Well, Valve wants you to chose their (upcoming) OS, as the OS to install on that media PC.
What’s really going on here is a long-term plan. My guess is, Valve wants to uncouple from Windows and Mac, and be able to provide a cheap (due to not having Windows or MacOS) “Steam Box” that you can just hook to your TV, and start playing games on. There are still two more announcements coming, each 50 hours apart. Our guess is the next one will be the announcement of a Valve-sanctioned/sold media PC, cheap, that comes with Steam OS. The one after that, who knows. Source 2 announcement perhaps?