AMD processors have all that stuff (North Bridge) on-chip.
While reading this I was thinking MiniMig-type of accelerator, but the device uses a real 68000 CPU. I think there was another post which mentioned 68k emulation in an FPGA, then clocking the hell out of it.
How would an FPGA emulated 68040 run on an accelerator? Could an FPGA emulate an '040 with an equivalent speed of 80MHz or more? Could it work in a standard Amiga accelerator, or would it require more electronics?
With the way we're moving along with technology, I would expect that we could build a 68000-compatible accelerator without a real 68k on-board.
But then, the question is who's going to front the money. Engineering Master's project, anyone? Seem like some of the best stuff came out of uni... :-)