If last Saturday night’s sneak-preview audience is any guide, this could be Julia Roberts’s biggest movie yet. Everything she did onscreen, everything she said either elicited ardent routs of laughter or sent what could only be called worshipful undulations rippling through the crowd. The thrall in which Roberts held these people frightened me. I’m sure execs at Universal Pictures are already peeing in their collective pants with anticipation over this weekend’s box office. Biggest opening ever for a March weekend — you read it here first.