Walking to The Shed, NYC's newest cultural center on West 30th Street and 11th Avenue, is a visual lesson in urban planning.  After exiting the A train on 34th Street at the eyesore that is Penn Station and crossing Eighth Avenue, signage indicates that there will be the new Moynihan Station.  (Among the many reasons to see Ed Norton's Motherless Brooklyn when it opens next month is the recreation of the original Penn Station.)   Heading towards 11th Ave. and the Hudson River are more glassy complexes way closer to completion than the long-delayed station.  There's also Neiman Marcus.  The Shed's physical address, 545 30th Street, is