The latest version of AMD's GPU Clock Tool gets support for the latest ATI graphics cards, the HD 4800 series.

The new version can be found over at overclex.net forum, and according to the post that can be found there, it comes with more options and settings than you could find in the rather limited Catalyst Control Center.

According to what we could see there are no obvious changes to the program itself. You can find the overclex.net forum post here.