Tonight I swapped out my original Sandy Bridge motherboard with one of the "Rev 3" B3 stepping (fixed) versions of the motherboard. It is an Asus P8P67 Pro.
After not being able to just boot off my Windows drive, I inserted the Windows 7 Professional install CD and ran the repair. That worked and I was back in business...
... That is, until I brought up my System Properties window using Windows + Pause/Break ... and found that I had 3 days to activate (because Windows had detected the hardware change.)
Trying to activate with via the Internet will bring you an error prompting you to buy a new key or try the automated phone activation service.
Use the automated phone activation service.
It's a pain in the butt because you have to hand enter or speak a bunch of numbers, then listen to and enter a bunch more into your activation dialog, but it works.
The automated system will ask how many computers this copy of Windows has been installed on. In my case it was the same system; I just swapped the motherboard, so I replied, "One."
It accepted it and gave me my code... seems I'm good now.
I hope the rest of you that have gone through the recall only have to deal with this inconvenience.