Try working with one for a week or two, make some prints, and then see if your firmly held beliefs are still so entrenched.
About a dozen of the photographers on my Antarctic Expedition were using 5Ds, and almost all also have 1Ds or 1Ds MKII bodies as well. What was amusing was how often the discussions at dinner turned to how astonishingly good the 5D images were - especially when it comes to low noise, all the way up to ISO 1600.
Without doubt the Nikon 200 will be an exceptionally fine camera, and it will put price pressure on the 5D, but the DSLR market is a fluid one, and there is a major trade show just around the corner.
Michael