See, the thing about Mary Sues is that it's not actually about what they do. All the over-the-top stuff with the amazing powers and how everyone loves them and how they're so beautiful is a symptom. The cause is how the writer feels about the character. When the writer is so attached to the character that they can't look at that character objectively and write them as a real person with strengths and weaknesses, but instead start doing anything (possibly going as far to break the rules of their own world) they can to make sure that that character always gets what the author wants... then you've got a Mary Sue.

And Metzen writes all Mary Sues, frankly.

WAIT WAIT WAIT hear me out-- **this isn't a bad thing.** It's a sign of a writer who has not fully matured. But Mary Sues can be a lot of fun-- see the wild, out-of-control success of the Twilight franchise. It isn't BAD, it doesn't make you an IRREDEEMABLE AND HORRIBLE person to write a Mary Sue. It does mean that you need to do a bit more work and possibly an editor who will call you on it. And I do think that WoW has the resources to be written by a professional, objective writer, rather than someone who loves his character too much.