I'm a great believer that it's a waste of time to try to get inside the head of any politician. As far as what I'm concerned, what they "really" think isn't our business. What counts is how they act, and what they say. Even for predicting future actions, it's more important to know what they've said and done (along with any relevant norms and incentives) than it is to know what they really think. Which, at any rate, we don't get to know.
All that said...I'd really love to know whether the Palin clan is entirely driven by petty revenge fantasies for mostly imagined slights, or if it's all an elaborate act.