The Catalyst 10.4 Linux package provides "early look" support for Ubuntu 10.04 LTS and finally it now supports the X.Org Server 1.7, which is used by Ubuntu 10.04 and most other new Linux distributions. It's been around since last October, but with the pending launch of Canonical's new Linux OS they have finally gotten around to supporting it.
Beyond the Ubuntu 10.04 / X.Org Server 1.7 support, there's a few bug-fixes and other items, but nothing too exciting.
There's also some reporting that Unigine Heaven/Tropics is now working better among other improvements. Download the generic Catalyst 10.4 Linux driver package here.