Ashlee Simpson's big comeback tour has been temporarily derailed in Tokyo, after she collapsed and was hospitalized following performance on MTV Japan Thursday. The "Catch Me When I Fall" singer, on the road to support her chart-topping I Am Me--and to prove to the world that she really can sing--remains in an undisclosed hospital, publicist Rob Shuter said Friday. News of the hospitalization was first reported by Us Weekly, which said Simpson had just finished a rendition of the hit single "Boyfriend" before telling the audience that she felt sick. "I love you guys," she said before exiting, only to...