Putting a Xeon in a non-up-gradable machine is such a pointless waste. Xeon aren't "better" chips. They are the exact same in every way as their non-Xeon versions save that they
last longer and have ECC capabilities.
Also, all this talk of heat generation is misplaced. It won't generate more heat because its a Xeon.
Apple hasn't learned a single thing from the failure that is the nMP. This iMac "Pro" is nMP 2.0 with a prepackaged monitor.
Granted, it might sell a bit better to idiots with cash who have no idea what a Xeon is.
edit: oh hey look what i found in less than 3 seconds of google searching: