I still see Canon's path as pretty obvious and easy.
I'm bookmarking this so I can quote you in 2013 :-)
Nicely fills out the line, giving consumers and pros more choices and helps transition buyer to two bodies each.
But why would Canon want to split the former two bodies (40d/5d) into *five* different ones (70d/7d2/6d/5d3/5dhd)? Sure this gives people more choices, but Canon is about making money and this variety also creates confusion and more support and manufacturing costs.
Imho if they expand the ff line they'll drop one of the crop cameras, i.e. no 7d2 but a bumped up 70d. And your "5d hd" might be very well an expensive "1d hd" at first because the people really wanting a $3000 36mp sensor have switched to Nikon by now.