I think you both make very valid points. Palin has to get thicker skin, and savvier press people. Having said that, the daughter/A-Rod comment was so low, so beneath even the lowest standard of decency, she had to comment. I would have shortened, and simplified her statement, but it is what it is.
I think Letterman, or the CBS suits, realized what a mistake he/they had made, especially Letterman with his first (worst) non-apology apology. His second statement was clearly more contrite and even heart-felt, probably wouldn't have happened unless Palin had commented personally.
I'm not clairvoyant, but these attacks aren't going to disappear should she decide to seek higher office. In fact, they'll worsen and increase, exponentially. I'm not entirely confident she, nor her family are ready for it.