If wildlife stills were the only goal I'd definitely rather have the 7D2 over the 5D3.
I'm not so sure about that. A friend of mine with a 70D took some test shots and I don't think the 70D performance at 1600 is all that much better than my 7D. If so, Canon needs some magic in that "low light sensitivity" improvement to the 20.2 Mpixel sensor to make the 7Dii worthwhile, IMO. Without a usable 1600 (or higher) ISO, I'm thinking I wasted all this time waiting for the 7Dii and maybe the 5Diii is the answer.
I'm definitely NOT pre-ordering.