Sarah Palin denounced this Newsweek cover as "out-of-context" and "sexist." Out of context because the photo was originally taken for Runner's World and sexist because Newsweek wouldn't have used a photo of Obama like that on its cover (maybe not, but the Washingtonian would).
Newsweek defended itself saying they chose "the most interesting image." I think it was no coincidence that they chose a photo of Palin in a "running suit" given the speculation of whether or not she will run in 2012.
But what really strikes me about the photo is Palin disrespecting the US flag. I guess she's glad that there are no penalties for violating the US Flag Code. Darn that activist Supreme Court putting the First Amendment above the flag.