I am a retired Boeing engineer. When planning a new passenger jet, Boeing would try fill unoccupied niches based on such factors as range, speed, carrying capacity, and airport compatibility, etc. Of course, in some cases, a new plane would replace an earlier model with improvements in fuel efficiency, ease of manufacture and other factors. I am curious as to what niche of photography that the D700 is designed for as it falls between the D3 and the D300. I think it great that one can use older lenses without encountering the "crop factor", but I don't think this is a prime Nikon marketing factor.