The release notes have yet to be officially published by Advanced Micro Devices to detail what is actually changed in this month's Linux driver update. However, when the PDF release notes have been uploaded, you can just expect them to say a few things.
The release notes should say there's now Ubuntu 10.10 production support (the Ubuntu Maverick release has been supported since Catalyst 10.10, but only now is it being sanctioned as being "production ready"), a few fixes, and perhaps the only interesting change worth noting are improvements to the GLX_EXT_texture_from_pixmap extension. With the GLX_EXT_texture_from_pixmap improvements, the GNOME 3.0 desktop experience may be better with Mutter, among other compositing window managers.
The fixes include Qt textures being white in some cases, a X segmentation fault, fixes for Unigine Heaven, and other minor work. There's also ongoing work towards reducing the size of this Catalyst Linux x86/x86_64 driver package, but even with Catalyst 10.12 the binary is still 120MB in size!
To download the obese driver package, download links are available in this forum thread.