Although 23-year-old Jason Wu designs dolls as well as clothes (hip dolls, that isrecent efforts include RuPaul and Amanda Lepore figures), his spring show displayed a great deal of maturity, with its focus on tasteful eveningwear in white, blush, and black. Wu's take on the omnipresent trapeze was discriminating: One faille coatdress had a princess line, and a shantung jacket had a Watteau back. Hems were often asymmetrical. He picked up on the ballet theme seen elsewhere this spring with pale tulle Degas dresses, and he offered several variations on the must-have navy blue evening gown. With only two collections under his belt, this Parsons- and Narciso Rodrigueztrained designer is still toying with his aesthetic, but the major stores are starting to take notice, and it'll be interesting to see how he plays his next hand.