First, hearty congratulations to the next Vice President of the United States. This bold step by John McCain promises to make this election a barn-burner of a contest.
One of the side effects of this decision, which I'm sure team Hillary was not anticipating, is to put Hillary into a tight spot regarding her maneuverings to become President. On the one hand, working wholeheartedly to elect Obama run the risk of delaying her chance for the Democratic nomination to 2016, by which point, her time will likely have passed in favor of a younger generation.
On the other hand, if McCain/Palin wins in 2008, the ascendency of a women like Susan Palin to the Vice Presidency and front-runner for the next open Republican Presidential nomination will vitiate most of the novelty (and symbolism) of Hillary running as the first women to run for President.
Either scenario weakens Hillary's position.
However, what's far more exciting is that Sarah Palin's candidacy will put an end to the false equation that women = pro-choice, eclipse the usurption of the women's movement by NARAL and other such groups, showing the nation the power of the pro-life women's movement.