Apple released EFI Firmware Updates for the MacBook, MacBook Pro, MacBook Air and iMac today. The firmware update descriptions are predictably short:
This update fixes several issues to improve the stability of [MacBook Air. Macbook, MacBook Pro, iMac] computers.
Users should note that while the EFI Firmware upgrades are downloaded by Software Update, they are not installed automatically. Instead, the updater is downloaded to Applications/Utilities and must be manually launched in order to update the firmware. Updating the firmware requires the computer to be shut down and it is installed on the next boot. Follow the included instructions carefully.
Apple also issued an Aluminum Keyboard firmware update:
This firmware update addresses an issue with the aluminum Apple Keyboard and the aluminum Apple Wireless Keyboard where a key may repeat unexpectedly while typing.
The updates can be found in your Mac OS X software update.