This is a total studio camera. From what I see, Canon did everything right. Dual Digic 5 to handle that massive data. Top end ISO limited to 6400 to improve dynamic range. I also think the SD/CF combo is smart too. Shooting tethered is a pain and Eye-Fi cards is a cheap way to transfer data off. Yes it would be relatively slow, but if you're in the studio you aren't shooting rapid-fire style. Data transfers should be fine. I think it will be called the 1DXs personally.
Editing these files... You will definitely need the fastest machine you can get X2. People already complain about the D800 files. But again, you shouldn't need to edit many files if you're in the studio.
Price I think will be $5000 - $5500 and for the designated user, I think is very reasonable. I think it's going to dust the Nikon D800, but should NOT be direct competition due to the price difference.
For the full-time pro, I think this camera is a huge home-run. I'd consider picking up this camera in a couple of years unless Canon comes out with a medium format camera....