updated 10:30 pm EDT, Wed October 26, 2011
Updates mostly debut or enhance Thunderbolt
Late in the day, Apple Support released a group of EFI firmware updates to recent Mac models, including the current iMac, Mac mini and MacBook Air models, along with one for the just-discontinued "early 2011" MacBook Pros and one for Lion 10.7.2 specifically. With all four EFI updates, the firmware is being modified to either support or enhance existing Apple Thunderbolt Display compatibility and Thunderbolt Target Disk Mode. In addition, the company released QuickTime 7.7.1 for Windows.
For the "early 2011" model iMacs, the update (v1.7, 3.69MB in size) enables Lion Recovery from an internet connection as well as the fixes for Thunderbolt Display and Target Mode compatibility. As is normal with EFI firmware updates, the update will force a restart on the iMac, after which a gray screen with a progress bar indicator appears, followed by another restart. Apple cautions that firmware updates much not be disturbed and machines must not lose power during the update, which may take several minutes.
For iMac users, the Boot ROM version number after the update is complete will be IM121.88Z.0047.B1D.1110171110. The update will not work with other models of iMac apart from the "early 2011" model which were sold after May 3rd. The update requires the machine be running OS X 10.6.8 or higher.
The Mac mini update (v1.4, 4.01MB) for the current model only includes all the fixes delivered in the earlier v1.3 update (which included Lion Recovery and the Thunderbolt fixes), but also resolves "several issues" to improve stability and is recommended for all users. The Boot ROM version on a successfully updated Mini will be MM51.88Z.0077.B0E.1110141154. The update will not work with earlier models, and requires OS X 10.7 or higher.
The MacBook Air update for the current model only (v2.2, 4MB) offers the same description as the Mac mini update: it includes the fixes from the previous 2.1 update but adds stability. The Boot ROM version on the Air following the update will be MBA41.88Z.0077.B0E.1110141154. It requires OS X 10.7 or higher.
The MacBook Pro update for early 2011 models (v2.2, 4.17MB) -- which were just replaced on Monday -- mirror the iMac update, enabling Lion Internet Recovery (if built-in recovery is unavailable) and fixing issues with Thunderbolt. The Boot ROM on a successfully updated MacBook Pro will be MBP81.0047.B1E. It requires OS X 10.7 or higher.
Apple has also released a general Thunderbolt update for Lion, targeting version 10.7.2 specifically. The update provides support for the Apple Thunderbolt Display and bug fixes for Thunderbolt compatibility. It is listed as version 1.1, and weighs in at 72.53MB.
QuickTime 7.7.1 for Windows (37.58MB) enhances security, addressing 12 vulnerabilities, and is recommended for all QuickTime 7 users on Windows. The fixes mostly close holes discovered by the TippingPoint Zero-Day Initiative. The current Mac version remains at 7.7.