It would a be a useful thing to stop using the term "pro" to refer to cameras. It is a misleading and incomplete term that tells us little about the equipment and, if anything, only a little about how it is positioned in the market.
The 5Ds/5DsR replacement camera is a great example. A high MP full-frame camera is, in fact, the thing that "pros" who need those qualities from a Canon system will choose, just as they do with the 5DsR.
I agree entirely. "Pro" is a vague term, as evidenced by the wide variety of opinions in this thread alone.
For the "physical" specs, I'd much rather hear about the camera in measurable / tangible terms such as metal vs plastic mounts, material the body is made of, weather sealing, etc. That at least has an indisputable meaning.
Personally, I still consider any camera capable of consistently producing high-quality images that can be used for a variety of commercial (i.e. money-making) purposes to be a professional camera. That's just my opinion. If someone needs a specific level of ruggedness or weather-sealing so be it, but I don't think that's the primary measure of a camera's worth in the "professional" world.