AMD has just released a Catalyst hot-fix driver for Linux users on this binary blob. This is the "AMD Catalyst 11.4b" driver.
All this hot-fix driver provides though is just AMD Radeon HD 6790 support, which is the newest graphics card in the HD 6xxx series family.
Beyond the HD 6790 support, there are no other official changes with this hot-fix. It doesn't have the X.Org Server 1.10 support like found in the Catalyst driver build for Ubuntu 11.04
that AMD pushed to Canonical.
This new driver can be found in this AMD knowledge base article