Let's assume a port of MorphOS to ARM (running in true big endian mode). Then we'd definitely need an m68k emulator. With that we'd have the same complexity we've now on PPC with Trance. About the necessity of a PPC emulator we could argue I'd say. But even if it was decided to have one, I think the m68k emulation layer and the PPC emulation layer would run alongside, not the m68k one on top of the PPC one. What makes operating systems slow is not the sheer amount of layers but the stacking of many layers.
