Turns out that Valve snuck out a beta update to Steam over the weekend, part of which was an early version of Desktop Theater. We already knew that Valve was planning something called Steam Desktop Theater, in which non-VR games could be used within their Vive headset (and, indeed, any other headsets which end up supporting the SteamVR APIs), but I wasn't expecting to see it until the first giant boxes full of matte-black hardware arrived at pre-orderers' houses.
