Not entirely true that they have to maintain the launch price thru the years at all cost.
The D1 launch price and the D3 launch price was miles apart.
my memory doesn't stretch back so far so I checked DPReview... suggested retail (launch) price D1 ~US$5,580, D3 ~US$5000, not that far apart considering when D1 was launched, Canon had yet to intro a pro model... 1D was launched 2 years later and even the non-pro build D30 was later than the D1... at that time, I believe everyone was still testing the waters... and it was still cheaper than the older Kodak based DSLRs...
1. Recession means less spending (not consumer but comapnies) means lesser demand at that price point. Cost is always the bottomline of any companies not the brand, brand loyalty goes as much as the $ can stretch.
like I mentioned, they would more likely than not cut actual market price sooner than later...
2. There are already existing cameras that fulfill about 80%(est) of what the D3X can do, at about 30-40% of the price. Hence there is no monopoly of product at that segment
and I believe that the Nikon strategy (and prob Canon's as well for the 1Ds) is that the D3X can do 80% of what medium format can do at ~1/2 the price and greater functionality in areas like autofocus, sensitivity, availability of accessories and lenses, NPS, higher framerate, etc. ...sure, not all studio shooters want all of these, and medium format has other advantages, but there are many who do want some of these in their camera system... and the medium format companies are starting to recognize and respond to this challenge...
3. Nikon is a few years behind its competitor for the same type of product and segment. Hence to set the price of D3x based on what the competitor set a few years back when market demands and conditions were different back then, is naive (in my opinion). Back then Canon 1Ds enjoy near monopoly of the full frame and even higher MP, ISO than Nikon. (The nearest competitor in full frame is Kodak). Not to say there was not even any competitor offering 70-80% of what they had at 30-40% of the price.
4. The segment which you are talking about was already cornered by Canon with the launch of the 1Ds a few years back, with many professional photog (in that segment) switching over from Nikon. Hence to take back what is lost (not to mention trying to wrestle over dominance of that segment, the D3X must be so revolutionary (like the D3) that ppl are willing to switch over at the same price. Or they(the photog) will be grossly be disadvantage by the advance technology, that the D3X offer. However, sad to say the D3X is not even a visible leap(not close to quantum leap) over its competitors (which was able to produce earlier) nor it has any price competitive edge.
I think the two of them will let the price settle itself over the years... they may undercut each other with specials and stuff but I doubt they would let their high end prestige product drop significantly in launch price because evidently people are paying good money for these top of the line products... for them I think the idea is "why rock the boat" in this segment... if they rock the boat, both of them will suffer...
which is why I think Nikon set the price point with both eyes open...
Lastly, no use for them to stick to their price rigidity and dream of ever launching a D4x, if they cannot survive this downturn (the worst since the Great Depression) - just look at what Toyota if facing now.
I believe Nikon thinks (and Toyota as well, but that's a different market, and a much more open and turbulent one where Toyota might prob survive better than its competitors) that it would not have trouble riding out the current financial situation and is looking at the longer term... whether that is gonna be the case, only time can tell... if the price is lower, obviously I would be happy as well

, just that the launch price is hardly, in my opinion, unexpected...
