Mamma Mia! star Meryl Streep Live With Regis & Kelly-Video.

It appears Oscar-winning screen gem Meryl Streep may have another box office smash on her hands. While it’s unlikely Mamma Mia! will conquer the wrath of The Dark Knight when it hits the North American box office on Friday, the film adaptation of the Broadway musical has already the Number One movie in the U.K.