The latest issue of Entertainment Weekly features a short mention of Justin about his involvement in “The Social Network” and his role for “Im.mortal” which appears to be confirmed:

“The Social Network”

“For the supporting role of Napster co-founder Sean Parker, the Silicon Valley VIP who introduces Mark to his high flying lifestyle, Fincher scored a particularly buzzy casting coup: Justin Timberlake. The music superstar has so far taken only occasional roles in films like 2007’s Alpha Dog and 2008’s Love Guru- much to Fincher’s confusion: “You can’t watch Justin on Saturday Night Live and not go ‘Why the f— isn’t this guy in the movie business?’”
Still Timberlake says his days as a pop idol prepared him well for working with the famously perfectionist director of Fight Club and The Curious Case of Benjamin Button. “In one of my first meetings with David, he said ‘Don’t worry, I’m not going to make you do a thousand takes,” recalls Timberlake. “And I said, ‘Listen, man I come from the stage. I’ve done the same show 200 times on tour, I have no problem with repetition.’”

“I’m.mortal”

The hottest project in town is I’m.mortal, a screenplay from writer-director Andrew Niccol (Gattaca) and young Hollywood is clamoring for roles. The sci-fi thriller is set to star Justin Timberlake and Amanda Seyfried and depicts a future where no one ages past 25. Overpopulation is controlled by allotting time as a currency- when you run out, you die. “Actors are very drawn to this” says producer Eric Newman who just added Inception’s Cillian Murphy. “It’s an opportunity to look their age but play a character who’s old.” As for the film’s ageless leading man, he says: “David Fincher’s The Social Network has put Justin into a different category. He’s a serious actor now.”

Thanks BlairWaldorf for the transcription

In other “Social network” related news, the official website released the dates the movie premieres in every corner of the world, click here to see which day the film goes out in your country.