http://www.macnn.com/articles/12/11/27/fixes.problem.with.some.thunderbolt.cables/
Apple posts Thunderbolt Firmware Update 1.1
updated 04:45 pm EST, Tue November 27, 2012
Fixes problem with 'some' Thunderbolt cables
Apple has released a small update for the 2012 MacBook Pro, Thunderbolt Firmware Update 1.1. The patch is described as fixing a problem with the notebook and "some Thunderbolt cables" that "may prevent bus-powered Thunderbolt devices from functioning properly." The file is 442KB, and requires OS X 10.7.4 or later.
Fresh-Faced Recruit
Joined: 02-01-06
So, I have a "MacBook Pro (mid 2012)" and am running "OS X Lion 10.7.4 or later" (10.8.2, in fact), but Software Update/App Store did not inform me of this update. So I downloaded it manually and tried to install it; I was then greeted with the message "Your computer's Thunderbolt port does not need this update." That explains why I did not get notified about it, but leads to the question: why not?
I'm going on the assumption that the update was included in Mountain Lion and is really only for Lion systems, but that is not clear from the description. Can anyone confirm/deny, or otherwise explain why my machine "does not need this update"?