The first Western Hemisphere game of the 2008 major league season will be played at the new Nationals ballpark. And, yes, the president has been invited. The Nationals announced Tuesday they will host the traditional Sunday night opener March 30 against the Braves at Nationals Park, the 41,000-seat stadium nearing completion along the Anacostia River. The major league season begins the week before when Boston plays Oakland in a two-game series in Tokyo.