As Obama's approval rating continues to dip, Hillary will incrementally distance herself from him and his policies. Whether it'll be enough remains to be seen. She's a very status-quo politician, and I think the electorate will be looking for someone who can sell themselves as a Washington outsider with a fresh perspective. Obviously none of them will actually fit the bill, but that'll the sales pitch. I don't think the slit between her legs will be enough to get her into office, the novelty of "the first _______ President" is slowly wearing off.
As for the GOP electing a woman, I doubt it. Sarah Palin might run since she's rapidly becoming irrelevant, but she wouldn't win. Bachmann is unelectable, and who else is there?