It's like Sam Raimi took a Final Draft file of his Army script, did a "Find + Replace" with a few key words, and cashed his check. Hell, even the protagonists are similar: They're both wisecracking, attractive womanizers who compensate for being out of their element by being incredibly resourceful and charming (though, to be fair, that's every action movie protagonist ever).
Jason Reitman: Up in the Air Is Thank You for Smoking
Who would have thought that the son of the guy who directed Twins, Kindergarten Cop, and Junior would become "the hope of cinema"? Jason Reitman is the acclaimed director behind movies as varied as Thank You for Smoking, a satire of the smoking debate that cuts both ways, and Up in the Air, the emotional journey of a man who discovers he's not as happy as he thinks he is despite looking like George Clooney. Yep, those two have nothing in common.
But They're Secretly the Same ...
Apparently, Jason Reitman's version of his father's "Arnold Schwarzenegger gets into shenanigans involving children/Danny DeVito" is "a charismatic jerk with an unusual job goes on a potentially life-changing journey." Even outside these two movies, all of Reitman's protagonists are likeable assholes: There's the smartass teenager in Juno and the smartass young adult in Young Adult.
Fox Searchlight Pictures, Paramount Pictures
Both of whom like married men and sleep with nerds.