Per the announcement at SteamCommunity.com, there's a new 01/06/13 Alchemist Beta that is mostly about Intel fixes. The dri2-xlib branch has been merged, a frame-buffer console kernel panic with Intel GPU fix, the SteamOS session screenshots by the Valve bug reporter were incorrect, support for full repaints in GNOME to provide reliable tear-free rendering, removed some PulseAudio hooks, and updated firmware packages to match the Debian Jessie kernel.
With this update, "Intel graphics are now supported out of the box; AMD graphics support still being worked on." As I showed last month when SteamOS was first unveiled and Valve said it was NVIDIA-only, Intel HD Graphics could work on SteamOS. Catalyst also does work on SteamOS but isn't officially supported over bugs. If you missed the earlier Phoronix comparisons, check out the SteamOS vs. Ubuntu comparison, SteamOS vs. Windows 8.1 comparison, and NVIDIA GeForce SteamOS graphics card comparison.
Valve also announced during their press conference on Monday about their Steam Machines hardware partners, which Phoronix had reported on earlier in the day with the 12+ companies bringing Steam Machines to market. Valve also might still end up offering their own Steam Machine system as retail.
Stay tuned for more details during the Consumer Electronics Show.