For most, price point will also matter. I know Nikon is typically considered Canon's competition, but in this case, I think Canon's own 5DIII is giving the hypothetical 7DII a lot of competition as the prices get closer. Canon had either get the 7DII specs (or an improved spec, such as DR) closer to the 5DIII if they want to price the 7DII >$2,200 or shoot for the 1 stop improvement and be sub $2,000 with the 7DII.18 MP. 21 MP. 24 MP. Even 15 MP. Frankly, I don't especially care. If it does a full stop or more better in terms of high ISO noise performance for RAW images vs. the 7D, a 7DII will be interesting to me. If not, no interest.
+1. And it better be more .
What would get my interest is the "mini-1DX" rumor with new sensor tech, 1.5-2 stop ISO performance, the finer grain noise of the 5DIII, and improved DR. That said, it is seems more and more likely that the 7DII will be more of a nice but modestl upgrade (1 stop ISO improvement, modest new sensor tech, 10 fps, hopefully better AF) but be priced at $1,600-$1,700. That would be a great camera for a lot of people, just not one I'll buy.