ATi have released an update in their driver series, moving it to version 4.6. The expected new Control panel has not made it into this release.
However, the driver features many new features and updates : ATi have improved the performance of their card in many areas (see release notes for more info). Asides from speed improvements, they have resolved many general issues, gaming issues, and wider program issues with this release.
ATi recommends that you should only upgrade if you are having issues with your existing drivers, and if you do, un-install the old drivers before installing the new ones.