Used Migration Assistant to migrate from Mac Mini (which is without iSight) to MacBook Pro (which has iSight). MacBook Pro was installed with OS X 10.6, then Software Update(d) to 10.6.8, before downloading Lion installer from Mac App Store.
What I've checked so far
– iSight camera is not detected by iChat, Photo Booth, Skype.
– System Profiler does not detect Camera under list of USB device
– There are AppleUSBDevices framework installed at the default location
with proper file permissions
I've also read through Google search results dating from 2006 to 2011.
Best Answer
[Adding update for posterity and closing this question]
Pleased to report my iSight was working in my MBP with a new logic board.