The imdb plot synopsis starts with "A forty-something preschool teacher looks to the personals for a change of pace and a relationship, with hilarious results." Diane Lane has been an adult for most of her career. Other than an I-can't-believe-that-was-her-in-The Outsiders, she's been a grownup.
This could be an important movie for John Cusack. Sure any movie that yeilds hilarious results is an important film in its own right, but this is his first "40-something" Romantic Comedy. He's been a lovable teenager, college kid, 20-something slacker, 30-something slacker, and a dreamy hitman who while also was 10 years out of High School, seemed a whole lot older to me than I do now in Grosse Pointe Blank.
If he can keep it up, John Cusack will be the next film legend, ranking with Paul Newman and Robert Redford, Dustin Hoffman and Jack Nicholson. Hell, he could be the next Sean freaking Connery. Minus the James Bond stuff.