I know it's faster, but that isn't anything amazing - computers are going to get faster anyway. Here are some of the problems that I believe it has
You seem to have an agenda that is intended to bash the new Mac Pro. Your post misses the entire point of the machine completely and totally.
Let's start with the specs:
1. No PCI slots - Thunderbolt is slower than pci and it also means that you have all the expansions all over your desk. Wires everywhere.
The new Mac Pro can support 43 pcie "slots". 43. There is no workstation in the world that can do that.
Thunderbolt is not slower than pcie. Thunderbolt is pcie 4x over a cable combined with displayport. Most motherboards only provide pcie 4x for the expansion ports outside the video card.
Here's a helpful hint too... There are no devices in the world that make use of pcie 8x and above except for video cards costing more than $600, and crazy storage solutions that write gigabytes of data per second.
There are work around a for both of these usage scenarios that mitigate any limitations. 99% of pcie cards are 8x or under or suffer a meaningless performance hit when run at 4x.
If cables REALLY bother you the I have the perfect solution.
No. The Mac Pro supports over 400 USB ports. What are you talking about? And don't tell me that it's too much trouble to instal USB hub. You're lazy if that's the case.
3. Non user replaceable parts
Every part is user replaceable. You have no idea what you are talking about.
What? What?
That's not actually true
6. Extreme price increase
Thunderbolt is slower than PCI and way more expensive. It seems like it isn't very practical?
Basically, what I'm trying to say is:
http://www.youtube.com/watch?v=F3XcUUZQqd0
You clearly just put together a list with the only intention being to bash the Mac Pro. You obviously do not have a real world usage scenario that is limited by the Mac Pro and you obviously did not think this through.
The fact of the matter is that the Mac Pro is better in every conceivable dimension than the last version. It is more expandable on every way. Smaller. Has more graphics computing power, supporting up to 17 GeForce Titan Black video cards or quatro cards. The old one didn't do SLI so you have 25% more gaming power than a single GeForce Titan Black with Dual D700's in crossfire. You can get 3 times more storage throughput with 24gb/s speeds, more pcie cards with expansion boxes etc. it's quieter, more power efficient, AND it's cheaper on a component level.
The only downside to the new Mac Pro is that it's new and there are new ways of integrating it and this scares people who are set in their ways.