Thunderbolt Firmware Update 1.0

I can't find the link to back me up but it actually does install. Had the issue on Lion as well. I checked display in system preferences and it was updated but continued to show me the update. I'll see if I can find the discussion

It’s been brought up before - it’s a known bug with Software update. My theory is that the update thinks it’s required due to a check that gets performed erroneously for some reason - probably a version number somewhere. It’s not needed because you already have it but it gets requested for some reason. Just ignore it since it won’t install again.

Apple is already aware of this undoubtedly and it’s been brought up here before. It seems to be a low priority to fix since it won’t install anyway.

I can confirm that I was able to install this update on Mountain Lion DP2 on two MacBook Pro's and an iMac. Originally I couldn't, but I tried again the other day and they installed.