Make no mistake; this is not a Linux desktop with Steam installed. This is a completely locked-down and customized installation of Linux designed to do one thing; run the Steam engine.
After tinkering in the operating system's underlying terminal code base, we forced the system to install Shutter by adding Debian's main repos. Upon doing so we realized that we'd break some applications by altering dependencies which in turn would break a facet of networking - not a good thing to do in a custom environment.
In some of our tests we found ourselves blocked from installing other applications specifically designed for Debian such as Chrome and even the open source Gimp image editing software.
As an extremely basic Linux system, SteamOS includes the aforementioned terminal app, a Firefox clone called Iceweasel, and a few other utility applications. Meanwhile, Valve has stated support for Netflix and other entertainment are forthcoming.
In general building a "Steam Machine" with Linux and Big Picture Mode would be a lot easier by simply installing Debian (or Ubuntu, or CentOS, or Arch, or any number of Linux distros) and then installing the Steam client on top. All go without the risk of bricking your machine or erasing all the data on your hard disk drives.
The installation process itself meanwhile is not for the faint of heart. For our own system we tested SteamOS on a relatively popular and recent PC setup with decent driver support even on Linux; pairing an Intel Core i5 3750K processor with a Nvidia GeForce GTX 670 graphics card.
The method that worked best for us was going with the custom installation, which we recommend extracting directly to a FAT32 formatted thumbdrive rather than copying and pasting files. Towards the middle of the process we also had to locate the Steam executable in Linux's file system to get it up and running. Also, be prepared to see lots of scary looking code.
Very early verdict
All in all, our conclusion is SteamOS shouldn't interest anyone without a completely spare machine that they can dedicate to SteamOS (as Valve intends) and not run anything else. Users for the most part would be better off just installing their own Linux flavor of choice and using the Steam client.
Valve may have released what is really an ultra beta to the Linux world, as it will appease the die-hard Linux folks or as a way to satiate those who aren't part of the lucky 300 Steam Machine owners. But for now, SteamOS is a task for the diehard tinkerers that love to potentially break things. Unless you can sudo command and can vi with the best of them, wait for the console to come out.
- We're in for plenty more Steam Machines and SteamOS at CES 2014.