Was it when the ninth silver minidress appeared on a spring 2007 catwalk that onlookers shut their notebooks and uttered a collective groan? Whatever the moment, a sense of fatigue and irrelevance hovered over much of the collections in New York and Milan. Sure, there had been some terrific exceptions: Marc Jacobs, Narciso Rodriguez, Oscar de la Renta, Marni, Prada, Bottega Veneta. But the fashion industry as a whole seemed to be asking the wrong questions: Was it time, in the breathy words of Justin Timberlake, to bring "sexy back"?No. Do grown women, as much as they may have enjoyed