Why Can't Reese Witherspoon Get First Billing?Correct us if we're wrong, but didn't Reese Witherspoon, y'know, win an Oscar just a few years ago? We're pretty sure she did, but you'd never know it from this poster for Four Christmases, the upcoming comedy she stars in with Vince Vaughn. Despite the fact that Vaughn fired UTA and his manager after the star vehicle Fred Claus opened to less than his first $20 million paycheck, the poster still gives him first billing over the Oscar-winning, A-list Witherspoon (and for another Christmas movie, no less!). To be fair, Witherspoon's last film Rendition was a box-office bust, but she wasn't top-billed on that, either: new beau Jake Gyllenhaal was, despite the fact that he's not yet proven himself as a box office draw. After winning the industry's highest award and proving her ability to single-handedly open a comedy with films like Legally Blonde and Sweet Home Alabama, what more does Witherspoon have to do to be called first in the billing block?Is it simply that studios are too terrified to give a woman first billing over a male star, lest people then think the film to be a chick flick? After all, Vaughn's last hit was The Break-Up, the rare romantic comedy with strong male appeal, something that marketing folks might have felt was in jeopardy had costar Jennifer Aniston been first-billed. Four Christmases isn't a romcom but a flat-out comedy, but would it be perceived as the former if Vaughn was subservient to Witherspoon in the billing block? Yes, when compared to Witherspoon, the presence of Vaughn in this film makes us more likely to see it (though still? not very likely), simply because the actor has a track record of enlivening even the most formulaic films with his improvised comic riffs. Still, we wonder just how B- and C-list you'd have to go to find a male costar whom the studio would allow Witherspoon to supplant. In an alternate Four Christmases, could the actress vault over Colin Farrell to claim first billing? Or will she have to settle for a part opposite Freddie Prinze Jr. to claim what, by rights, should be hers?