Piru wrote a nice report on the state of coldfire compatibility with the 68000 it is worth reading (sorry I can't remember the link). But basically, it will still need an emulator to run Amiga software, at which point you would probably consider a fast more modern processor.
I'm finding it hard to be impressed with seeing TOS at various resolutions... I installed GEM on my old PC years ago and I felt like I was using an ST...
