Fixed it :)
In device manager underneath imaging devices I saw "Webcam" -- before the botched fw update it said "Microsoft LifeCam Studio" and had a diff driver. I rolled back the driver (or if that doesn't work you can force it to use the one inside program files \ lifecam) then re-installed lifecam -- my cam now works. Now -- what's the deal with this update utility and why's it changing what driver the camera uses?