Madonna and Anne Hathaway are spending New Year’s in the exclusive mountain resort of Gstaad, Switzerland, at the chalet of design icon Valentino and his partner, Giancarlo Giammetti. Sources say Valentino is throwing a New Year’s Eve bash tonight at the luxe members-only Eagle Ski Club, and “rumors are flying that both Madonna and Anne Hathaway will take turns serenading the legendary designer, and they might even do a duet at midnight. Valentino’s NYE bash is the hottest ticket in Europe, and people are flying in from all over the world for it. Valentino is reportedly spending 500,000 euros on caviar, champagne, music, food, décor and fireworks at Wasserngrat Mountain. The source adds that Hathaway, who got married in a Valentino gown this year, will be accompanied by her husband, Adam Shulman, while Madonna has brought her daughter, Lourdes, 16. The hosts have been seen in the Swiss ski town this week with their pugs. Roman Polanski and Emmanuelle Seigner were also spotted.