THE BRIT IS BACK: Britney Spears makes her return as a cover girl today, her visage and bod gracing the front and insides of V Magazine’s spring issue. In the story that accompanies the photo spread, the 29-year-old Spears talks about how moptherhood has impacted her career. “I think it's easier to let people in when you're younger,” she points out, “but when I became a mother I wanted more privacy for myself and my children. A life away from my life." But the Brister hasn’t lost touch with her inner femme fatale. "The bitch is back and better than ever!" she promises. (3/2a)