if Apple chose to for example, keep the same design of this case, rip out 1 of the GPU's and then give a cheaper option for the other GPU, while keeping the ECC ram, Xeon CPU, and everything else thats amazingly fast, but sell it for 1,999 instead of 2,999, as a base I think it woudl have been a better option.
Then let the who want those GPU's upgrade to them or better if they need them.
edit: removing the use of consumer: i'm using it differently than I think most people intend in this particular conversation. when I say consumers, I mean everyone and anyone with purchasing power, including professionals, prosumers and the like.
You make a good point but now you are entering top of the line iMac territory. Most people who buy an MP want the dual gpu. As much as I think your idea is great I just don't see how it'll be better than the top iMac.