....and I'll say it again - Canon should never have made the 7D as good as it is functionally with a crop sensor. It's like putting a lawn-mower engine into a BMW convertible.
I should know as I own two 5DMarkII's and a 7D. I bought the 7D thinking it would be close to the 5D in image quality, or at least in the same ballpark. I was excited by its features and thought I could live with a small drop in IQ for the sake of all those other goodies. Unfortunately it's not even close. Makes sense though - the 5D Mark II has 2.56 times the surface area for the sensor, and sensor technology improves, but rarely by that amount in a year. The crop factor at 1.6x really does make a big difference.
So the current lineup is just freaking bizarre. In fact it's horrible. Here's why:
1. You have a fantastically featured awesome little camera with great autofocus, button layout, flash trigger capabilities, weather sealing, responsiveness...yadda yadda yadda.... but with a horrible sensor (by pro standards OK - compared to 5D Mark II) that make shots look very point-n-click like in the noise department, and even in the low light color rendition. That's the current 7D.
If you are distance limited, the 7D sensor delivers a touch better than the 5D2, so what was so wrong with a little aps-c camera with better performance? Lots of people liked it.
And APS-C is less expensive and it's not like it performs that badly even when not distance limited, sure not as well as FF, although if you adjust aperture to make up for DOF the performance becomes much closer.
That lineup is just whack and they should really do a sensor swap. Canon will address this by putting crop sensors solely back into the XXD line with the 70D, and boosting the features of the 5DmarkIII so they meet or surpass the 7D - guaranteed. Well shots per second *might* be down a bit, and there will be no onboard flash but these are the only exceptions I can think of). If they did kill the 7D line and put most of it's great features into the next 5D, then look out for a 5Dx moniker.
certainly nothing wrong with boosting small body FF specs, I've been asking for that for ages but I don't think it has to kill off the 7D, at least unless it has at least 30-36MP sensor density and APS-C crop mode.