Shared yesterday evening is that Steam VR support of beta quality is built into the latest Steam client and just requires activation via starting up the client with the "-vr" switch after opting into the SteamVR beta. This mode shows the Steam Big Picture Mode on VR devices.
Valve sees VR support as another big step for the company and they'll be talking more about these ambitions -- along with Linux gaming and SteamOS / Steam Machines -- at Steam Dev Days over the next few days.
At the moment on Steam are just 14 games supporting VR, many of which games are also supported under Linux. However, expect for that number of VR-supported games to rise greatly over 2014.
Details on enabling the beta VR support in Steam can be found via this SteamCommunity.com page.