Valve fixed one of my big issues with Steam Machines... kinda. Games with their own launchers (e.g. Trine 3, Starbound, and Evoland) won’t, well, launch. Valve has removed the SteamOS-compatible tag from around 35 games. Some devs are working on new launchers. Fingers crossed that everything’s resolved by release day.
Curious about Valve's new SteamOS? Eurogamer's Digital Foundry takes the beta version of the new TV-friendly operating system through its paces, finding some issues that hold the OS back but allowing that it "could well be the direction PC gaming needs to find a home in the living room."