So... we are assuming the Mac Pros are "overpriced" because today's low-end Mac Pro offers about the same performance as last year's mid-level Mac Pro for $500 more?
The only valid basis of comparison for pricing of the Mac Pro is to compare it to machines using identical processors and subsystems from folks such as Dell and HP. Only then can you assess whether the Mac Pro is "overpriced" or not. You have to compare the Mac Pro to its mainstream competition, not to previous Mac Pro price history. Obviously the Nehalem architecture has changed things a little bit in terms of pricing. We assume that we know the whole story, but we don't.
Do Dell and HP have Nehalem yet? If so, what are their prices? If not, shouldn't we wait for the competition to at least CATCH UP before condemning the Mac Pro?
Comparison between CPU pricing between generations is a perfectly valid comparison simply because that is precisely how Intel does things. Intel has fairly stable price points and when new models are released they directly replace processors in existing price points. Often older models remain at the same price point, alongside their replacements, and don't drop in price.
Case in point is the new 2.66GHz T9550 Core 2 Duo processor that Apple just introduced in the 15.4" MacBook Pro to replace the previous 2.53GHz T9400. Apple didn't put in a more expensive processor, the 2.66GHz T9550 costs $316 and directly replaces the 2.53GHz T9400, which Intel is continuing to sell at $316. So Apple gets the 2.66GHz T9550 for no additional cost and they just decided to pass that on to consumers.
Regardless of factors in performance, the raw CPU value of a system is based on what price point of CPU you choose to put in.
In the case of the Mac Pro, the previous standard configuration offered 2 x 2.80GHz E5462 Harpertown Xeon at $797 each for $1594 worth of processors in a $2799 system. The new standard Mac Pro configuration offers 1 x 2.66GHz 3500 series Nehalem based Xeon, most likely the W3520 Bloomfield which costs $284. It's basically a Core i7 920 with additional verification. So before you had a $2799 system with $1594 worth of processors and now you have a $2499 system with $284 worth of processors. Apple reduced the price by $300, but they are still using $1000 cheaper processors.
Now Nehalem may be more expensive to design for, and the new Mac Pro does have layout changes, but is it worth $1000? Keep in mind that the new Nehalem processors have the memory controller bundled into the price now since it's on chip. Thermal requirements are also reduced since the old Mac Pro had to deal with 2 x 150W TDP processors, while the new ones only have to deal with 2 x 95W TDP processors. ECC DDR3 is also cooler than FB-DIMMs. The new CPU tray design is also enabled by Nehalem since the memory controller is on the CPU allowing a simple combined CPU/memory tray and would have been a lot more expensive and difficult to due before with Harpertown and an off-chip memory controller.
The previous 2.80GHz E5462 Harpertown remains at the $797 price point and it's direct replacement in it's price category is the 2.53GHz E5540 Gainestown which sells for $744 and is capable of dual processor configuration unlike the 3500 series Nehalem that Apple uses in the $2499 Mac Pro. The 2.26GHz E5520 only costs $373 each. Regardless of performance, so even if the new configuration is faster, Apple is now using processors at significantly lower price points than before, without a corresponding drop in Mac Pro pricing. Granted Intel may be charging Apple more for first dibs on Nehalem, but the difference isn't 20% or even 50%, it's several fold.
The evidence:
Price for 2.80GHz E5462 on last page and remains unchanged from the original $797 launch price even after the most recent Feb 09 price adjustments:
http://files.shareholder.com/downlo...1EA-87F8-410F752F12EF/Feb_22_09_1ku_Price.pdf
Launch pricing for 2.66GHz W3520 at $284:
http://www.tomshardware.com/news/intel-product-roadmap-2009,6384.html