If it's all digital logic, you can do this now with FPGAs. Modern ones would have no trouble implementing something like a 68030, and the tools can synthesize it from Verilog.
The great thing about FPGAs is that if you have a bug (which never happens to me, but I hear it happens to other people) you can fix it and recompile in minutes.
This is still in the realm of what someone can manage entirely in the head. I'd love to have a service which I could send an HDL of something around this complexity and get the chip on my doorstep. I'd like it also to have a reasonable cost.