I think it's worth seeing the photo in its original context. Here's the shoot--where Palin took a variety of photos, in a variety of garments. And here's the piece. The photo in the shorts is just one of many. Here's Runner's World on the photos:
On the cover of this week's issue of Newsweek is a photo that was shot for the August 2009 issue of Runner's World, in which Sarah Palin was featured on the monthly "I'm a Runner" back page. Runner's World did not provide Newsweek with the image. Instead, it was provided to Newsweek by the photographer's stock agency, without Runner's World's knowledge or permission.
One more thing--I think if you're really concerned about equality, be that gender, ethnic, religious whatever, you have to come terms with the fact that this means equality even for individuals you don't much like. It means equality for people who you feel consciously exploit inequality for their own individual gain.
You don't get to infer that Juan Williams is a porch monkey because you disagree with him. You don't get to objectify Sarah Palin because you think she's an awful person. Not if you expect people to take your concerns seriously. I said this already, but it bears repeating--a principle applied only to people you like, mocks that principal. We don't raise these questions about gender for Sarah Palin's benefit--we do it for our own.