All Radeon HD 5000-series GPUs and later products are supported, so anyone with a three year old AMD system should be covered. In addition the update brings a long list of bug fixes and improvements.
Here’s the changelog:
Fixed Steam controller firmware upgrade process
Updated AMD Catalyst driver to preview release 13.11 Beta 9.9
Fixed crashes on Intel graphics by merging Keith Packard's dri2-xlib branch
Fixed an fbcon kernel panic with Intel graphics
Fixed a problem where SteamOS session screenshots taken by the Valve bug reporter would be incorrect
Enabled full repaints in the GNOME compositor for reliable tear-free rendering
Removed startup and shutdown hooks from the pulseaudio package, fixing the transition to system-wide mode on upgrade
Updated firmware packages to match the Debian Jessie kernel
Updated Intel graphics stack to Mesa 10.0.1
Applied an Intel kernel fix to re-enable KMS support
Fixed a problem where Trine 2 could cause audio to stop working by restricting direct audio access to the sound server
Enabled audio from the desktop session; the default audio device is still hardcoded to discrete graphics HDMI audio for now
Enabled 3D passthrough in the VMWare driver
Fixed Steam controller firmware upgrade by adding USB auto-mounting
Added NTP time support
Added XDG directory helpers
Added text feedback when building kernel drivers during first boot
SteamOS is shaping up to be an interesting alternative to mainstream consoles and traditional gaming PCs in some scenarios. More than a dozen companies have already announced or showcased their Steam Machines and the community seems to be taking notice. It is still too early to say whether SteamOS will be a hit, but it appears to be moving along nicely.
