Look at the sample photos on the canon site for all their lenses and cameras. About 90% of them look like crap, and taken by some dude on the street that they handed a camera to.
I agree that the pics a not that appetizing, but search Flickr for 5Dii pics and you will see that they are incredible. I have a hard time believing that canon didn't at least improve on them.
To me, everyone said that the 5D2 was the perfect camera minus AF and lower useable ISO. It looks like the addressed that and much more. I think the only thing people are bummed about is the huge price increase, and the fact that it is pricier than its Nikon rival. I think Canon must be pretty sure of HW sweet this thing is to price it where they did.
But, who knows. In the end I think they are probably both going to be amazing cameras and ones that a good photographer will be able to take amazing pics with. I don't see a reason to switch, but then again I am heavily invested in Canon with lens, flashes, triggers, etc. I also love the Canon system on the camera, and I don't want to learn a new one.
Either way I think you will be happy with either camera and some good glass. I'm not even considering switching, but I don't think I can blame someone for doing it.