Meanwhile Team Fortress 2 is not working on Legacy Catalyst 12.6 due to a missing OpenGL extension.
Unless AMD releases a feature updated Legacy driver, you won't be able to play (at least) this Source game
using the proprietary driver on a still quite powerful GPU as the Radeon HD 4800 is.
Let's see if such a Legacy driver will be released. I doubt it. :/
Ah, and xserver 1.13 support would be highly appreciated...