I wish I had some valid reason to pick one up. My Mac Pro 1.1 is a bit long in the tooth. Even though this was a base model, it was crazy-fast. Click on the iPhoto icon in the dock and the the photos opens right up. My machine takes well over a minute. SSD running at PCIe speed, current Xeon processor running a good GHz faster than my Xeons, it all adds up. The new Mac Pro is absolutely silent, but my old Mac Pro hardly makes any noise except for the HDDs, so it's nice to see they maintained a low-dB office mate. There is a slight breeze at idle, but I didn't have anything on-hand I could use to tax the CPU and GPUs to judge thermal management.
The case is something you need to touch if you get the chance to do so. It's also great for making highly-distorted selfies (2nd picture)
It's the new Apple Mac Pro, the Macintosh workstation aimed at video professionals, pro photographers, and people with disposable income who want a Mac. MSRP starts at $2,999 for the 4-core processor with 12 GB RAM & 256 GB SSD, and works its way up to $9,599 for the 12-core, 64 GB, 1,024 GB SSD, and dual AMD D700 graphics.
It's about 12" high and 6-1/2" in diameter. All of the expansion is external so you're either happy with what it comes with, or you're turning your desktop into a collection of expansion bricks and cables. Pros don't care. Biggest surprise is Apple doesn't include the keyboard or a pointing device with this Mac Pro. I guess they wanted the smallest box possible.