BEST FOOT FORWARD: Listen, we all have to think positive this season. That means no one is gonna be sitting around in Nats Park, depressed and staring at their shoes. However! Should the worst happen... maybe at least they can be Nats shoes. Sorry, does that sound too defeatist already? We are trying to be optimistic. At any rate, Vans and Major League Baseball will be offering a Nationals shoe-and-jersey combo ($300) in its Opening Day Collection, reports Mr. Irrelevant. Only 12 of these sets will be available, and they go on sale April 5, the day of the Nats' home opener against the Philadelphia Phillies. GET IT: Commonwealth, 1781 Florida Ave. N.W.; 202-265-1830.