In some anally-retentive circles, you might need this-or-that qualifictaion just to be 'an editor', but to get a *good* editor, you need someone who has a love and respect for the title and a want to take it to new heights. Andy, during his Thargdom, has had these in shed-loads.
To reiterate, I think that the qualities sought for an editor vary from title to title. I've heard that you can become an editor at DC Thomson by girating on grumpy men's laps in the board room,wearing nothing but a Desparate Dan mask and a tutu.