It'll determine for Republicans the fitness of Palin for a presidential run. If her shit smells clean after this, she is your candidate in 2012.
Her credibility lies mostly with the frindge, after the many embarassing moments spawned from her own inediquacy as a candidate her chances at the presidency are really low from my pov. Specially with the republicans taking back the house, and the sad fact that their lies and fear mongering turned the public opinion against Obama. The republicans could possibly take 2012 with any half decent candidate with the set up they are building.