Chex, Canon actually had 2 large bodies, the 1D and 1Ds lines. They've now 'combined' the two large bodies into one but have continued on with incremental improvements to the 5D.
Bernard, wrt inflation you're probably talking about headline inflation (e.g., CPI). CPI isn't a good gauge because it includes highly volatile components such as food and energy. The more relevant figure; and the one policy makers follow, is core inflation which removes that volatility. Core inflation in the last, just over, 4 years (not 5 since the D700 was announced in July 2008
) has been in the range of 2% per year in most of the G8 countries (not sure about the G20 but it has some less stable countries in it) and includes, for many countries, a deflationary period in late 2008 and much of 2009. This is very, very low and would not lead, on that basis alone, to any significant increase in prices over that time. It is; however, a fact that electronics and computer components exhibit disinflation in pricing. That's why we get successive generations of equipment with better performance at the same or better prices. As far as the JPY/USD exchange rate losing 60% of its value, on July 14, 2008 (I'm using that as a proxy for the announce date of the D700 since I don't know the exact date), the Yen was at 106.8. It is now at 77.65. That is a drop of about 27.3%. Not near the 60% you tout. Factoring in the two components of price disinflation and the exchange rate, without access to some modeling I'd suggest there's probably more profit in the D800 than there was in the D700 which would, on a relative basis, put it higher in the model line than the D700.
The target market of the D600 - if it's presumed to be people moving up from DX bodies, and to borrow a couple other people's thoughts that they'll use it with a Tamron all-in-one lens or the basic kit lens - "needs" 24MP? Wants? I'll grant wants. Needs? Not so much.
Josh, given the money that Sony has been bleeding for the past number of years, their pockets ain't all that deep.
David, I worked for a Japanese company for 6 years. Believe me, they want to beat their fellow Japanese competitors just as badly as N.A. companies do.