Michael's got a series of interviews with Paul Barnett over at his site. I've said before that Barnett seems like one of the better developers in the industry, and it's comments like these that continue to reinforce that view.
"The only balancing you should do [post-release] is if there is something that fundamentally breaks the game."
He later clarified that comment here:
"There is no need to obsessively mess with the game. I hate the nerf train, I hate designers who just won't leave it alone they think they know best. I belive that you should only mess with these things when it is clear they are breaking the game."
In short, MMOs don't have to be the fickle, fluid blobs they are currently... looking completely different every 6 months. Among other problems, this invites players to hate the game because they're always thinking about what it could be, what it should have been. MMOs are not services. They're products with services necessarily attached. Finish the damn product and leave it alone.