This is the kind of camera that makes people change systems.
Ouch!! Way to throw Molotovs on a Canon forum!
Actually, I don't really agree, but it could certainly have an impact on new entrants to the FF market. The system-change-inducing camera was the Nikon D800/D800E (and, perhaps, the 5D mk iii, for all the disgruntled D700 owners put off by too many megapixels).
Plus, I think the 7D mk ii could be system-change-inducing camera as well, because it is something that Nikon doesn't yet have - a true replacement to the D300s. The D7100 is very nice, but for serious sports / wildlife etc the 7D ii will probably be all over it (buffer, fps, focus etc). However, if Canon could have released the 7D ii with a relevant lens such as a refresh of the 100-400, 300 f/4 or 400 f/5.6 then it might have been a stronger punch into the ribs of Nikon.
The D750 will probably have the effect of dragging down 5D mk iii prices, and resale values.