Apple has released firmware updates for five Mac products, including the MacBook Air, MacBook, MacBook Pro, iMac and Aluminum Keyboard Firmware.
There are no notes from Apple that detail the specific changes in each of the firmware updates. All of the computer firmware updates say they fix "several issues to improve the stability" of the computers.
The exception is the Aluminum Keyboard Firmware. Apple says this firmware update addresses an issue with the aluminium Apple Keyboard and the aluminium Apple Wireless Keyboard where a key may repeat unexpectedly while typing. The update also addresses other issues, although they were not specified. Mac OS X 10.5.2 is required before installing this update.
Apple also released a downloadable Firmware Restoration CD. All of the updates are available from Apple's website as separate downloads.