WebMoniker: I've been waiting and salivating on the rumours about this camera for months and Canon have in my mind blown it. A FF prosumer camera should have an in built flash. End of story. Absolute deal breaker for me. What were you thinking of? I don't think I can be bothered waiting for the next 'improvement' to the range. I want an affordable FF DSLR with in built flash and I think I know where I can get it!
Canon's FF cameras are not cheap whether they are prosumer or not. I suspect most people will purchase good glass to take advantage of the FF sensor. Canon's best lenses are their L series lenses. As I replied in another post unless Canon redesigns the mechanism the built-in flash will not pop up high enough. Most if not all of Canons L series lenses are large and they block a portion of the flash's light path resulting in a circular shadow at the botton of the image, especially if you are using a lens hood. I never use the pop-up flash on my 50D for this reason. I am sure there are other design considerations but if I were to purchase a 6D or even a 5D the lack of a pop-up flash means I am not paying for a feature I could not (or would not) use.
Amtext: I had my 7D stolen in March, have been using an old, beat-up Nikon since then and was anxiously awaiting what Canon would release so I could spend the insurance money that's dying to be spent. Would love to go FF and thought the 6D would be it but.... no. No fill flash is a deal breaker for me, slower frames per second a huge disappointment, and the layout - more like a 60D - not appealing since I'm used to the 7D, though this is not a deal breaker. As for fewer auto-focus points, it remains to be seen, but it sure seems underwhelming on first glance. (I never had any problems with the 7D's auto focus.) The 6D is a huge disappointment on paper. Nice though they are, I don't really care about GPS and WiFI. I'm leaning toward replacing the 7D and am even tempted by the 5D MK II (and welcome any advice) given the appealing prices for each,
I agree with Canoman regarding pop-up flashes. Although there is something to be said about the convenience of pop-up flashes I do not use the one on my 50D. Unless Canon redesigned the mechanism the built-in flash does not pop up high enough. Most if not all of Canons L series lenses are large enough to block a certain portion of the flash's light path resulting in a circular shadow at the botton of the image, especially if you are using a lens hood.