SteamOS 01/13/2014 has fixes for multiple issues reported by users on GitHub. The latest SteamOS also merges in various Debian Wheezy bug-fixes for a handful of packages. UInput is also now built into the kernel directly rather than as a module and it's accessible via the Steam user. One of the more important bug-fixes is to address two cursors appearing on the screen when a game was exiting.
SteamOS 01/13/2014 also has reduced CPU and GPU usage while gaming by interrupting the Big Picture Mode and overlay rendering. There's also a fix for AMD tearing issues by having the SteamOS compositor request vertical retrace synchronization rather than relying upon the implementation's defaults.
Last but not least making this update exciting for Linux enthusiasts is broadened Debian compatibility. There's improved compatibility with Debian Wheezy repositories by widening the SteamOS binary package repository.
More details on this latest SteamOS Linux update can be found at SteamCommunity.com.