AMD's Catalyst 10.10 proprietary Linux driver has initial support for X.Org Server 1.9 and thereby "early look support" for Ubuntu 10.10 and other distributions using this very latest xorg-server. Catalyst 10.10 also carries v-sync fixes, 2D acceleration improvements for their newer 2D architecture, Compiz fixes, and various other work.
There's also Linux support for the Radeon HD 6850 / Radeon HD 6870, however, it's first-cut support and really have no idea how it performs with these GPUs that were released yesterday or what features are working or not. AMD or their AIB partners have yet to send us any Radeon HD 6000 series hardware, so Linux users are currently left in the dark. Regardless, we expect though that the support for these next-generation GPUs will be refined over the coming months with their monthly Catalyst updates.
This release for Linux should also carry proper OpenGL ES 2.0 support, openSUSE 11.3 production support, corruption in Xinerama mode, and addressing xorg-server segmentation faults when VT switching back to a running server.
The official AMD Catalyst 10.10 release notes for this Linux driver have yet to be published, but those are the notes for this Catalyst 10.10 / fglrx 8.78 driver that come to mind for the information we know. Overall the Catalyst 10.10 Linux driver should be rather nice and fixes up a number of things from the testing we have done to the driver over the past several weeks, but sadly the XvBA video acceleration support is not in any better shape.
The direct download link for Catalyst 10.10 on x86/x86_64 Linux can be found in this forum thread.