Two romantic comedies for the price of one ensue when a producer of Hollywood trailers (Cameron Diaz) and a Surrey-based newspaper editor (Kate Winslet), both recoiling from failed relationships, suddenly decide to trade domiciles over the Christmas holidays. And because this was written and directed by chick-flick specialist Nancy Meyers (What Women Want, Something’s Gotta Give), both women score hyperbolicallyDiaz with Jude Law, Winslet with Jack Black and (less romantically) Eli Wallach. The problem is that happy endings this strident and overextended begin to seem somewhat desperate. PG-13, 138 min. (JR)