Eduardo Romero and Andreas Radke of the Arch Linux project feel the Catalyst Linux driver is "in a pitiful state and AMD is doing close to nothing to improve the situation, they just take Linux as a joke." As a result of them not liking this ATI driver, it's going to be moved out of Arch's extra repository and into AUR or Community, which puts it in a lesser state.
While they do not like the Catalyst driver, they do like the RadeonHD driver even though its capabilities are currently limited on the newer R600/700 generations and it doesn't yet implement all of the GPU-supported features like reliable power management. Eduardo had said, "In the other hand the radeonhd driver, which is in extra shows some promise, and so far have been good, they have been able to make a good driver with only some documentation released by AMD, when AMD can't make one while being the makers, go figure out."
Eduardo's mailing list message about their revolt against the ATI Catalyst Linux driver can be read here along with their on going mailing list discussion.
Additional information on this situation (including a more detailed response from Arch Linux) can be found in our forums.