To me, (perhaps because Riscos was part of my childhood) the hardware is falling behind, and emulators are for people stuck in the past. What I'd be interested in is something new. The things I liked about Risc Os are the clean file organisation (app dirs/extendible file system), the customizability, the ease of programming, the extensive use of drag and drop, the clean UI (not having window furniture take up 30% of screenspace), snappy small programs, !Draw, memory mangement... and more like that. All of these things could be incorporated into a new system. Building a new system from scratch would be difficult, but there's no need to build things from scratch. Small OSes are popping up all the time and source code is so available that even insignificant projects can compile lots of software. ROX is an interesting development for making linux more RiscOsy. Something like that but a little more radical would be just what I'm looking for. The linux habit of scattering things all over the place is a little tedious, but having a linux kernel would be fine.
I don't care any more about backwards compatibility, what I care about now, is that the things that RiscOs brought to the world aren't lost. I miss them now and have missed them ever since I left it behind.