I'd be pleased to see transparent emulation in AROS. In the past from what I remember, it had been said that they had no intention of doing any sort of emulation, but I think it would be a useful thing if it could be done.
The real problem was that no one had the motivation to do it, it could be tricky and will require quite a bit of work.
If John wants to give it a go, that's excellent!!! He will get the full support of the AROS team including testing and bug fixes. :-)