Apple has released EFI updates for the new iMac and 13-inch Retina Display MacBook Pro — iMac EFI Update 2.0 and MacBook Pro EFI Retina EFI Update 1.1, respectively.
According go Apple, the updates address Thunderbolt and Wi-Fi issues, along with sleep-related problems. They also include general performance fixes.
You can learn more about iMac EFI Update 2.0 at http://support.apple.com/kb/DL1618?viewlocale=en_US&locale=en_US . You can learn more about MacBook Pro Retina EFI Update 1.1 at http://support.apple.com/kb/DL1619 . Both require OS X 10.8.1 or higher.