Why can't other bodies handle the FW update?
I'm guessing its a function they just recently added to their software, and its not in any camera they released before 2012?
Makes sense really, as it would save them a lot of repair time for something like this if all their bodies could just download the firmware
@preppyak, you posted something about additional contacts discussed in another thread, seems you deleted that? Got a reference? I see the same 8 pins on the 5DII and 5DIII.
I can't see it being hardware based (I could be wrong), but I suspect Canon feels it would be a waste of resources to issue firmware updates for all bodies to provide the capability.
At least postage would be cheap for the 40/2.8. If you own a MkII supertele that needs the firmware updated and don't have a 2012 body, it would be cheaper to rent a T4i for the 3-4 day minimum just to apply the update than to send (with insurance) the lens to Canon...