With the handgrip, the S2 is about the same size as the D3x (or D700 with handgrip).
Interesting to me is the bayonet-diameter/sensor size vs. flange distance-ratio. What is the flange distance of the S-System? Less than 55mm (I think the R was 46mm)? That gives the optical designers more freedom.
While the primes are really big in comparison to the N/C-lenses, the 30-90 seems tiny! I wonder why it's about the size of the 35mm, while in other systems the varios are huge (and quite often lose more than one stop)?
The S2 has simply less battery power: 18.5Wh (7,4V@2500mAh), while the D3x has 27,8Wh (11,1V@2500mAh). I hope the ASIC saves power, because the batteries of the M8 are simply too small, the big shutter, the DSPs and the "hungry" CCD with those small batteries (3,7V@1900mAh = 7Wh!) go down really fast, especially in the cold.
Regarding the R&D-effort: from my experience, in every project you reach a critical size limit, more and more manpower has to be invested into communication/documentation making if less efficient. I have worked in such big companies (much larger than Nikon) and it's horrifying to see how much resources are spend into management/controlling/documention/auditing, while smaller companies are more flexible and "intuitive". Around 100 people in R&D for the S-System instead of ~ 500 people in D3/D3x-R&D are maybe ideal for this kind of project!? Although certain things that are done by Nikon in-house (microprocessor development, production processes) are handled by suppliers for Leica - so it's propably not really 100 vs. 500 people anyway.