May 2, 2012, 22:39
Lensrentals, who received their first shipment of "fixed" 5D Mark IIIs from Canon, have done a teardown to inspect what has actually been fixed. Looks like it's just a tape job...
http://www.canonrumors.com/2012/05/the-5d-mark-iii-fix/
http://www.canonrumors.com/2012/05/the-5d-mark-iii-fix/