This is why I don't pull additions or major changes to RPC commands without at least a couple of people looking at them and either saying "yup, that's exactly how I would do it" or "it'd be better if...."
I agree with Mike, the -coinbaser <cmd> should be separate from setauxwork.
Does setauxwork interact with the new getmemorypool RPC command at all? Should it?
And should there be a listauxwork RPC command?