Whether or not they will put the 5D3's AF in the 7D2 remains to be seen.
Completely different size aps-c vs ff... but that is not necessarily a bad thing since it's probably easier to put a larger af point spread in a aps-c than a ff, so the 7d2 af might even have an edge for tracking across the whole frame.
cant i ask why 6d hasnt got the features the 7d has? if im paying more money for something that is supposedly above it in a camera range (going from 1-7, generally the cameras get better and more expensive) then surely i can ask why the 7d has so many more af points or a better body casing or a better iso performance etc etc
Except for the price of the ff sensor there is a decisive difference - the 6d has a big brother and Canon doesn't want to cannibalize their 5d3 sales, while the 7d2 will be the top of the aps-c line so Canon can put everything in it and people will still pay the price because aps-c and ff have different markets (sports/wildlife vs portrait/event). If and when the 70d arrives you'll see the the same feature-cut procedure of the 6d again.