It seems that the media and even Obama have forgotten that it's McCain running for President, not Sarah Palin. Oh yes, we get the rhetoric of "she's only a heartbeat away from being president" but who knows when someone will die. As of right now he's perfectly healthy and who hasn't heard of someone being declared terminally ill and still living long after anyone expected. The argument is asinine.
Running against Sarah Palin will not win Obama votes. Instead he needs to counter the enthusiasm for her with his own enthusiasm. Give the voters concrete answers and numbers to what your 'change' will be. As they always say... the best defense is a good offense.