It could have been Rihannas shining moment: the cover of Vogue! But when the nude pictures hit cyberspace, her once-in-a-lifetime chance was gone in a flash. Rihanna and Vogue editor-in-chief Anna Wintour had been talking for weeks about doing the cover and an inside spread, says a close friend of the singer, who adds that the two even chatted about it at the Met Costume Institute Gala on May 4. Anna told her Vogue absolutely loves her and really wanted to work with her. Rihanna was ecstatic! But since the photos came out, says the friend, Anna hasnt returned any of her calls. Rihannas so upset!