So back to my original question, is there still interest?
I would say yes, if it were still being updated, tweeked, etc. there would be a BIG interest... But...
Is it just the legality keeping it from use?
Yes and no. The main issue (and an extremely watered down version of it) was that different parts were owned by two people, one of whom became very bitter and refused to work with anyone, AND because the Amiga IP was traded around like a hot potato. So not only were several different entities demanding fees for using Amiga IP, there was also internal strife that AFAIK is still not patched up to this day.
Is it the fact that it's somewhere between hard and impossible to set up on current hardware?
I would say no because you could use it's latest release on "old" cheap hardware and still have a blazing fast Amiga. Anything built up from that would be amazing!
Maybe it sounds good on paper but you didn't use it?
It is illegal to sell or buy it since the big blow up. That is why very few use it, IMHO.
Has Aros negated the need?
Has it? I'd say no, not yet. Will it? Most likely.
I see Amithalon Vs. Aros kindda like Amiga Vs PCs in the 90s. Since Amithalon is not being developed (Like Commodore did to the Amiga) AROS will catch up and surpass it (Like the PC did to the Amiga mid 90s).