Marc said: [ Simon, isn't the smaller sensor Nikon argument similar to Hasselbalds "square" argument before the H camera? ]
Not quite the same Marc, but I do get your point and agree that these companies make statements that serve their purpose at the time.
The Hasselblad square argument was in its own right a sound one - more area than 6x4.5; less bulk than 6x7 gear; no need to rotate the camera....
I suppose that the H series 6x4.5 with the AF and "auto-everything" technology necessary to meet market / user changed expectations of the day, was simply not supported with any rationale for moving away from 6x6. To my mind that rationale was the need to use a smaller frame to: keep the overall camera / lens size manageable (it is just about the same overall bulk as the V series 6x6); enable reasonably/comparatively fast functionality that would be more challenging in a 6x6 version .... etc etc... But still today Hasselblad has really not commented about that shift (nor its shift to Fujinon).
But, in Nikon's DSLR case, it really was blindingly obvious to most that the lack of a full-frame DSLR was due to things like: the F lens mount "throat" is relatively small thus creating real challenges for the design engineers; they don't make their own sensors....
That small "throat" issue arose from the days when AF became the norm - Canon bit the bullet and changed its mount enabling a wider throat for the necessarily bulkier lenses and data-bus needs. It knew that many pro customers may take the opportunity to move to Nikon - Canon held its breath and weathered the storm, which ultimately was not too damaging.
On the other hand, Nikon lived by its legacy customer-pitch that served it well - "our lenses can be used on all vintage bodies". But the digi-era posed a challenge no one could predict and which necessitated "larger" throats anyway. Canon benefited from its much earlier decision. Nikon suffered from its decision (IMHO).
But while we all knew Canon's full frame high end technology was superior due to one matter of physics that applied to all capture media: "bigger is better" (ceteris paribus of course); Nikon really fed the market with much bull-dust saying its cropped frame technology was superior. But, alas, now it joins the ranks of full frame pro-DSLR.
To my mind the Nikon scenario was just not very credible.
Further as Hasselblad is likely to move to say a 45MP sensor (the race is on and the Hasselblad brand is likely to keep wanting to look like the market leader!), it may be that the next step beyond that is to move closer towards a full frame 6x4.5 sensor! Maybe...?
Well, we live in interesting times; who knows what is around the corner!