"Boeing says ... the popularity of the MD-11 as a freighter ...."
Bet them Boeing boys are slapping themselves on the back for having the foresight to run bulldozers over the MD-11 tooling after they bought the Long Beach MD plant.
The 777 doesn't have near the fuselage strength of the Mighty Dog, and thus will require a ground-up redesign a la A330F. It will cost much more as well.
So instead of selling an off-the-shelf freighter, they'll have to launch a whole new program, or convince customers to "upsize" to the 747-400. Incredible foresight.