Spears rings in the New Year in Sin City. Plus: Hilary Duff, Mandy & Wilmer and more

IT'S THEIR BIRTHDAY

She has the day off, but nothing can tear a disguised Meredith Vieira away from the Today show! Pretending to be Matt Lauer's biggest fan, Vieira surprised her cohost Friday morning for an early celebration: both share the same birthday – Dec. 30.