AMD has done their monthly roundabout and released the ATI Catalyst 10.1 Linux driver. Found in the Catalyst 10.1 driver change-log is "Ubuntu 9.10 production support", even though AMD seeded them with an unreleased Catalyst driver since September
and the official Catalyst releases since October have worked just fine with Ubuntu 9.10. Besides the "support" for Karmic Koala there are bug-fixes and they include a few AMDCCCLE / Catalyst Control Center fixes, HDMI hot-plugging fixes, and more. There are also updates packaging scripts from Phorogit
and better OpenGL 3.x support. There is, however, still about a page of known issues and that's just their public list.
Catalyst 10.1 for Linux continues to lack X Server 1.7 support, but the Linux 2.6.32 kernel may work with this release. Like past months, the Catalyst 10.1 driver is another unexciting driver update. AMD Eyefinity
might also be working on Linux, or at least the ability to use three monitors from a single AMD Radeon HD 5000 series graphics card, but that hasn't been officially shared. Catalyst 10.2 will be a bit more exciting as Ubuntu 10.04 nears, but not without some disappointments too.
Download links for AMD Catalyst 10.1 can be found on the Phoronix Forums