On C) Yes I have 2 iMacs one a recent and love it, but still need a beast to run windows and osx. I don't like to take that space on my iMacs. I have also had a drive fail in 2 iMacs and I do like to have access to expand on dev machines. Swapping a video card or drive really is not fun on iMacs.
On D) I agree, I was overreacting to my tool of over 5 years going away. As long as the update comes through like Cook said. If not I feel Apple is making a mistake and this reflects on the CEO and direction, believing too much in 'post-pc'.
However, I do know what I am talking about regarding gamedev needs. Windows is part of that in parallels or bootcamp and a portion of your drives - including enough processor and memory to run both, if there is no 2013 refresh changes will take place in gamedev'ing for Apple. That will be a clear signal the biggest machine is the iMac.
Apple is a hardware company, they should always have something like the Mac Pro that is a market need/demand even if it is not directly as profitable. 4-5 years for an update and only a hint of an update does not leave one satisfied. Cook has been in charge at least half that time.
If they don't have a beast to buy that I can swap out the video card on or add a drive easily on occasion that means a windows tower will be back in my office. I got rid of the last one a year ago for parallels and bootcamp but only run that on Mac Pro now. It isn't like they play in the low end commodity desktop market, this is high end, higher margins than most. Passing on good customers if they bail.