Two advantages that haven't been mentioned about Palin:

1) Cash. The McCain campaign says they've pulled in $7 million since the announcement.

2) Shock. The pick caught everyone by surprise, including the Obama camp:

Mr. Obama's advisers said that compared with the mountains of data they had gathered on Mr. Pawlenty and Mr. Romney, they had far less information on Ms. Palin. Their dossier consisted of a thin document based mainly on her run for governor and newspaper clips about an investigation into whether she was involved in pressing a top state law enforcement official to dismiss her sister's former husband from the state police. And, they said, given her short time in high office, there is relatively little video of her readily available.