The celebrity designer wheel keeps on turning. The latest star to join the club is Gossip Girl Michelle Trachtenberg. She is teaming up with Coach to design a costume jewelry line under its Poppy label — faux pearls and colorful crystals hit stores in the Spring.Though there isn't an official deal in the works, Super Claudia Schiffer has also expressed interest in designing. "I have no definite first product in mind, but I would love to do cashmere. It's something I wear all the time myself, but I'd love to do something a bit more price-friendly. . . . Or I could imagine doing handbags," she said. Cool, but not everyone is thrilled with these celebrity designer deals. According to fashion writer Robin Givhan, "I can't imagine Donna Karan saying I'm going to cut an album because her friends say she can sing karaoke." Ouch. Do you agree?