How Much Retouching is Too Much?

By now most people know that even famous supermodels don't always look as great as they appear in magazines. Digital photo editing can create and remove things once only possible with plastic surgery. A few swipes of a mouse can remove gray hair, beauty spots, scars, wrinkles, extra weight, extra chins, saggy eyes etc. You get the point right?

For many people, retouching is expected when they hire a professional photographer. Is there a happy median or is it a situation of the more the better?

Here's an example, what do you think?