The finalists are:
Pauline Maier, Ratification: The People Debate the Constitution, 1787-1788.
Jack Rakove, Revolutionaries: A New History History of the Invention of America
Alan Taylor, The Civil War of 1812: American Citizens, British Subjects, Irish Rebels, & Indian Allies.
My money is on Taylor.
For more about the George Washington Book Prize and the finalists check out the press release at the C.V. Starr Center for the Study of the American Experience.
What a competition! Those are three incredibly gifted scholars who have all contributed significant books.
John might be right that Taylor will win, but I think Maier's work is pretty impressive, too.