On Wednesday evening, she waltzed into the White House for the formal State Dinner wearing a white Chanel Spring 2009 couture gown -- the same one she wore to the 2009 Costume Institute Gala at the Met.Anna swept past reporters last night (stopping only to mention that her dress was by Chanel, natch) then joined guests including George Clooney, Harvey Weinstein, Marchesa designer Georgina Chapman