Purely from a financial perspective it would make sense for Nikon to consolidate the line, as there is almost no functional difference between the two, and they have not sold anywhere close to the numbers anticipated to meet financial projections.
In that regard however, the proposed 'upgrades' would not be of of the significance many consumers would expect for a 'consolidated' model (ala 1Dx and D4). The upgrades are basically software and a badge, sans the processor - which in the end is technically still a software upgrade.. The new processor will provide the muscle needed for a different AF algorithm, noise reduction algorithm (the alleged ISO improvement), moire suppression algorithm, and sRAW (which if based on the D4 implementation will be a waste of processor cycles anyway..) oh, and let us not forget the crucial addition of GPS! (sic).
No.. What I see in this consolidation is simply an attempt to restore faith in the Nikon brand. Showing their base that when they see something wrong, or lacking in tangible benefit, they react - and decisively - to trim the fat and produce the lean mean product they should have released initially. (queue the I AM xxxxxxx theme music)
As for the 'new' model.. In my opinion they could gain back their D700 base (the ~790k they thought would upgrade) if they would take current tech in a lower mp sensor (akin to the D4) yielding better overall ISO, DR across the ISO range, color and tone across the ISO range (all without the unnecessary processing) faster fps, robust AF, 1080p video, and stuff it all into a body that is more comfortable to hold (they still have the D700 castings, heh) with truly needed ergonomic changes like moving ISO and AF mode selection to the right side so you do not have to transfer perch of the camera back and forth between your right and left hands. There is already a large hole in the body due to the flash for wireless communication, but not important either way there.
If they want to run a body like that along with a high-mp body that fewer people need/want, that would make multiple bodies more feasible all around.