In this Nikon D3x article (also from the Nikon Pro magazine) Tim Andrew shares his first impressions with the Nikon D3x (he was one of the photographers to work on the D3x brochure):
"The D3x gave medium-format looking files with all the flexibility of the Nikkor Lens system"
The sample files he is referring to will be on Nikon's web site on Monday. We shall see. If this is the case, there may not be a medium format Nikon.