I thought the Intel Xeon W 2xxx Cascade Lake CPUs were just drop in replacements for the existing Xeon W 1xxx Skylake CPUs in the existing iMac Pros needing just an EFI update on the chipset? Kind of lazy of Apple not to do a basic CPU refresh. GPU updates would require hardware changes though and I guess they felt if wasn't worth it if they refreshed the CPUs but not the GPUs.
Why would they, if they decided this was a one-off product . . . just to tide a sub-sub-audience over until a) the redesigned Mac Pro could be released; and b) until Intel released its updated consumer product . . . which took far longer to get out than Intel told the entire world? The deltas seem to be:
i) The color. Still valid.
ii) ECC memory. This matters to smaller and smaller portion, and the majority of those can probably justify the extra cost of a Mac Pro setup
iii) The higher number of cpu cores. Again, Mac Pro is the answer now, though also 10 higher performing cores is now possible in the regular model.
iv) Webcam. Now in the regular model.
v) Four TB3 ports. Still valid.
vi) Better cooling setup. Unclear, but since a Fusion Drive is still possible, they probably did not change too much internally. So probably still valid.
vii) Lots more memory. Still valid, but no as much with 128GB now possible in the regular model.
viii) T2 processor. Now in the regular model.
ix) 10Gb ethernet. Now in the regular model.
x) Bigger SSD. Now reversed (4TB in the Pro vs 8TB in the regular)
xi) Graphics can vary a great deal based on compute unit numbers, architectures, and memory. But for many tasks, the regular model will now be faster.
So . . . . the color, ECC memory, double the TB3 ports, and better cooling (possibly). Very few people should choose the older platform at this point. Apply looses very little by simply end-of-life-ing the base cpu, and I would guess few worksites would really need an update to it. I'm sure those same worksites would want a cheaper well-provisioned Mac Pro, but that is a different point.
Tangential point . . I hope they have not removed the memory door in the regular model. Easy adding your own memory is a great thing in this product, I think.