Although John McCain hails his running mate as a model of ethical behavior in office, the State of Alaska would apparently disagree: it is investigating Palin for abuse of power in office. Palin, without explanation, recently fired a state employee, who now claims that Palin pressured him to fire a state trooper who was, at the time, embroiled in a messy divorce with Palin’s sister. Read more about the story here.
Unfortunately, the investigation seems likely to take several months, so Palin, even if guilty, is unlikely to be under indictment by the date of the November election.
In fact Palin's "October Surprise" is already scheduled to arrive on Halloween. There's plenty of people who don't want that train to arrive on time, but we're watching them now, right?