There are some valid questions being asked about those images by the Nikon Rumors folks. Are the D700 images upsized to make them look poorer? At best, there is little we can tell from them without more information.
ISO 3200 noise on the D800 looks closer to ISO 6400 on my 5D MK II, and I know it should be better than that. ISO 6400 seems very noisy, and only usable with a lot of NR. However, NR tends to work better on high MP images, so the end result should be good prints at 6400. We really do not know exactly what settings were used or if the camera was a prototype. If both images had been compared at 1:1, I wouold have a better idea of the performance.
I certainly believe its the right camera for studio photographers and for landscapes, some wanting to use it for general walk around use will have to learn to deal with 100+ mp tif files if they use tif in their current workflow.
i'll certainly be following it once it gets out into the hands of more users.