The Hollywood publicity machine seems to think that the best way to promote a movie is with celebrity relationships. Tom Cruise is not in love with Katie Holmes. Katie Holmes, or her ridiculous love life is not the reason I'm going to see Batman Begins. Batman is. And, shit, Tom Cruise isn't what's making me interested in seeing War of the Worlds. If anything, he might make me not want to see it, what with his screwed up cult of Scientology (yes, it's a cult - where they try to steal your money).
Furthermore, anyone who thinks that a relationship between Brad Pitt and Angelina Jolie could ever last longer than a world wide press tour is pretty much an idiot. They might get back together for the DVD release, but that's as far as it's going to go.
Sure, celebrity relationships get people talking about the stars and their movies, but it's all just so tacky. If Angelina Jolie is in your movie, here's how you promote the damn thing.
Also, get her to wear a leather dress to the premiere. That might help too.