The main problem with the Mac Pro is that it's in fact a 7 year old design, assuming they designed it in 2006 and didn't simply release it then and it's actually a 2005 design!
It isn't. Earliest some of the design parameters were locked into place in 2007 but likely most of the work went in during 2008.
This isn't just Apple. All the major workstation vendors Xeon workstation design stay stable for an entire Intel Tick/tock cycle. In the enterprise space few if any are looking to churn all of the computers on a 12 month pace.
There's been bus speed improvements but
But? It isn't just speed improvements. At Nehalem ( the 2009 model ) Intel ditched their whole "front side bus" design finally. It did not scale well past 4 cores. The current Mac Pros are significantly different at a architectural level than the 2006-2008 era models.
If the functional requirements of the case are the same why should it change. That limited change is also a superficial observation. Internals changed substantially. If have a well designed exterior modifying the internals shouldn't cause many large changes.
same 4 or 8 RAM slots even when that means redundant slots to obtain full triple channel speeds,
Eh? The fact that the slot are connectted to three different controllers is different than the single ones in the 2006-8 era means they are not the same. Again superficial observation of generic DIMM slots is the only thing driving "sameness" here.
The SATA III (6Gb/s) standard was not even presented in draft form until July 2008 and ratified later that year. The 2009 Mac Pro probably had frozen specs at that point. The 2010 reuses 2009 infrastructure, just like all other vendors in this class. There were other workstations with more SATA connectors but not necessarily faster ones.
SATA III being the default connectivity showed up only 2012 workstation models. Yes Apple is late but the pace being implied here as way behind the curve doesn't really mesh.
same case, same everything accept the GPU/CPUs. It can't justify it's price tag either.
It isn't the same. The value, not the price point is the primary problem. They are a very overdue for a refresh. Given Apple's uncharacteristic forward looking comments likely indicates that they know it.
They could end up pleasing a lot of people if they just start been a bit fairer with pricing, even if that means a cheaper model as a BTO option.
They just need to update. An Xeon E5 1620 4 core model would not have a problem putting a small amount of distance between the upper end iMac and the entry Mac Pro.
The problem has been in part Intel. They are ones who didn't update the full range of options for the 3600 series from the 3500 series. ( initially only one and never were any quad core updates ).
If get off the edges of the Mac Pro line up (entry and extreme top end) the value isn't that far off what it has been versus the competitors. If the user has workload in the wheelhouse of those machines they make sense.
The Mac Pro never was a please everybody with everything product offering.
Component prices have gone down signficantly over the past 7 years or so,
just the RAM alone is about a fifth of the price comparing a 2006 to 2010 Mac Pro (Current model simply being a 2010 Mac Pro with a minor speed bump).
Well if you wanted Mac Pro' to come standard with just 1GB of RAM I suspect you'd find most prospective Mac Pro users at issue with that configuration. The offset to lower component prices is to provide more. Instead of 1GB standard RAM in 2006 the 2012 Models come with 6GB. That is a 6x increase for your 5x decrease. That is indicative of providing value not the lack of it.
Likewise the 2006 Mac Pro came with 250GB HDD and the 2012 models come with 1TB ones ( a 4x improvement). You could downgrade the 2006 Model with just a 160GB HDD. That is a 6x improvement in capacity. HDD prices are not cratering right now.
The power supply is larger in 2012. The PCI-e slot bandwidth is much higher than 2006. It should be higher still if had already moved to new Xeon E5 class offerings and PCI-e v3.0.
In short, if get more than can pay just as much instead of the overall price going down. That is basically Apple's strategy across the Mac line up. As component prices go down, put in "more" of the component. Or move to a more modern more expensive component ( SSDs vs HDDs in the laptop line up).
Going "down" in price points means changing Mac models. If want to follow more affordable components then user needs to transition to a another model.
The Mac Pro has drifted. Apple should try to an entry (or BTO downgrade) back into the $2100-2300 range (before taxes ) but haven't so far.