Jason Wu picked up the Fashion Group International's Rising Star Award for women's ready-to-wear last month. Watching his Fall collection, it wasn't hard to see why. Just five seasons in, the 25-year-old's clothes display a sophistication of hand and of sensibility that have won him a loyal following of young socialites and starlets. For fall, it looks as though he'd like to extend his reach to working womenas-yet-untested territory for this designer. Among the cocktail and party dresses he loves to design were wide-leg, oversize herringbone trousers worn with silky bow-front blouses. And he showed his first-ever knits: snug sweaters topping full, calf-skimming skirts. Though pretty enough, these inevitably invoked Miuccia Prada's influential resort collection, as did the floral prints he used for deb dresses with soft V-necks, twisted bodices, and flaring skirts. In contrast, a pair of micropleat dressesone strapless and to the knee and the other a belted, floor-length halter stylehad a fresh appeal all Wu's own.