I’m just reading now ‘Curating Subjects’, and in first essay (by Andreasen&Larsen) is a proposition to consider a term ‘middleman’ instead of ‘mediator’ in the context of art word. In my opinion it brings mainly economic aspect in the foreground. The term ‘mediator’ (which btw is very often according to authors used by Obrist for his precursors, I assume before 90’) is charged with heroic connotations and a struggle to restore order (think ‘EU mediator’).