Well anyway, I'm sticking to my theory. If Nikon rolls out the D400 in the next two months, I think we may see the 70D sensor in the 7D. If Nikon does nothing in the fall and Canon holds off until sometime in 2014, I think the odds of a shiny new sensor go up significantly.
I don't want to look a triple ditto gift horse in the mouth, but...
I'm not certain the 7D2 is just waiting for a Canon "Execute build plan delta!" audible to be called from corporate in quick response to a Nikon offering. I'm sure they'd love to, but does it work that way?
I don't think the sensor decision (in particular) is a plug-and-play variable in the design. I'm an engineer (not a EE to be fair), but wouldn't an 11th hour sensor decision drive a lot of other issues, like processor bandwidth, LiveView control firmware, rate-limiting the shutter to not overheat the processor / fill the buffer too soon, etc. Also, doesn't the board + sensor have a specialized mount with power and heat sink considerations?
Just thinking out loud... Maybe it could
be as Unfocused has said if Canon's development process banked things as they went. It's possible that they have a banked 'vanilla' 7D2 design (only so-so, think '70D plus
') ready for manufacture should Nikon offer the D400, but could concurrently be working on a more badass variant should the competition take longer with their designs... As much as we believe Canon has armies of engineers and dozen of design variants (to some extent I am sure they do), it would be horrifically inefficient to take many concepts all the way to near-production prep like that.
(...but it would SO explain why new products take so damn long with Canon.