Now you're talking. I think this would solve one half of the problem, by getting in early - though I still think mediators could do with a bit of help learning some skills.
-- ambi
Yes, mediators definitely need to get in earlier. And it might be a good idea to allow for multi-party mediation if there's 2 distinct viewpoints being argued.
Also, it was mentioned earlier that Wikipedia as a written medium isn't the optimal place for mediation. I tend to disagree. The most important aspect - the mediator "forcing" the parties to get to the bottom (and therefore the real issues) of their disagreement - should still work just as well as collaborative editing does. Collaborative editing may not be as effective as face-to-face teamwork, but it still works. And I believe that mediation, if performed before things escalate could work just as well.
--Mgm