The OP and others have very logical thinking regarding such things as product lines, competition, marketing, and so forth ... and also seem to have a lot of knowledge about those particular things. I, on the other hand, don't pay attention to the various events/shows/marketing strategies, nor am I familiar with every camera body out there, nor do I follow anything Nikon or anyone else is doing. I hear some gasps
Not only that, but I've never used a pro body or full-frame body - I have a 7D and it's all I use (actually, I have 2 of them). The only input I can give in this discussion is speaking to my feelings about the 7D and what I'd like to see in the mk2.
I currently am shooting more wildlife and birds. The APS-C sensor is a huge boon. I use a 500 f4 IS II lens and 1.4x much of the time, and even that combo on a crop sensor is often not enough reach for many birds and smaller wildlife. People that have never actually tried shooting birds, have a hard time understanding how much magnification is really needed. I'm talking about getting the subject large enough in frame to avoid having to crop away all of your resolution, details, and making noise more prominent in the process.
IMO, the most critical thing that absolutely must be present is an appreciable increase in IQ / reduced noise. Without that, the mk2 would be (almost) useless to me, personally. Regardless of MP, FPS, and other specs, we need better noise performance at reasonable ISO's from 1000+ which is commonly needed for wildlife shooting. I'm usually dialed in around ISO 800 - 1250 ...1250 is sometimes usable especially if you ETTR, but around 1600 or so the IQ is degraded far too much for my taste. Anyway, I will be ecstatic if there is increased IQ / reduced noise.
After the IQ increase, my next requirement would be an improved AF system. Although I've never used a pro body, and the 7D is the best camera I've used so far, I have no problem in saying that the 7D AF is not up to what I need. There are too many AF fails, particularly in less than ideal light, with moving subjects (wildlife). Especially with birds in flight, the AF performance in the 7D is lacking. But, it was not meant to be a pro body, so I am understanding of the various shortcomings, and that is why I am still relatively happy with it given the price I paid (not outrageously high).
Frankly, if it were not for the APS-C 1.6x that I need for wildlife, I would have gone full-frame long ago. The IQ, AF, and MP on the FF bodies totally destroy the 7D, but I simply cannot give up the extra reach of the APS-C.
If, on top of an IQ increase, they could squeeze a few more MP in, I would not complain.
As far as FPS, I would be fine with an increase, but the 7D's 8 is fine with me.
I never was really interested in GPS or WIFI capabilities, but I'm sure if they are there I will like/use them...especially since I will probably be paying an arm and a leg for them...not that I didn't already use my other arm and leg to pay for the 500 f4
As far as the speculation on a more pro body style, I would be elated to see it happen. I stay in Manual Mode always, so losing the knob and other stuff that isn't necessary and can inadvertently be bumped would be welcome. Additionally, the integrated vertical grip style body like the 1 series would be awesome. I have the 7D battery grip. It is essentially useless to me when shooting wildlife, because I need to select different focus points with the thumb joystick on-the-fly as I am shooting moving subjects. The 7D battery grip obviously does not have the thumb joystick, nor can you reach the built-in body joystick when gripping the battery grip vertically. I rarely shoot vertical wildlife shots simply because I cannot select focus points and control everything easily in vertical format with the subject is moving. If the 7Dmk2 has the pro body with integrated grip similar to the 1D-x with the thumb joystick and everything, I would be thrilled.
Well, those are my thoughts for now, from a nature shooter's perspective. I am excited to see what happens.