Which Book is Jason Reitman Adapting for his Next Movie?

Jason Reitman has been very tight lipped about his next film project. What we know so far is that he was working on a screenplay when he came across Diablo Cody's Juno script (prompting him to cease work on said mystery script). MTV was able to squeeze a few more details out of Retiman

"Yeah, I'm writing something," he grinned, cryptically. "I'm going to direct it at the end of the year. And no, I haven't told anyone what it is yet." "It's a comedy and a drama [book adaptation]. Think 'Thank You for Smoking,' but instead of political it's corporate."

He also revealed that he is writing one of the roles for Reitman regular J.K. Simmons (who played Ellen Page's father in Juno and Aaron Eckhart's boss in Thank You For Smoking).

So I want to send this question out to the /Film Readers: Does anyone have any ideas which book Reitman could be adapting? Tell us in the comments below!