Last night there was a SteamOS 01/07/14 Alchemist Beta update and besides fixing the Steam Controller firmware upgrade process, it also updated the AMD Catalysy driver. The Catalyst driver now packaged is a "preview release 13.11 Beta 9.9."
Former NVIDIA Linux engineer turned Valve employee and Phoronix reader, Pierre-Loup A. Griffais, mentioned as a comment to the SteamOS beta update, "This update upgrades the Catalyst driver in our repositories with a preview release. This build should fix the poor in-game performance and malfunctioning return to desktop functionality. Known problems include tearing and poor overlay performance in-game; please install them and post your feedback!"
Hopefully AMD will have out an official Catalyst Linux graphics driver update of 2014 out soon given that the Kaveri APUs are beginning to ship next week, there's still many AMD Linux gaming bugs to be fixed, and the Radeon R9 290 Linux performance is bad.