Deadline and originally scooped by LatinoReview. While we've been hearing talk of Joel Edgerton and other well known names the studio has gone with Renner. The prequel will focus on the early day of Treadstone and will leave the window open for Matt Damon to return but Bourne will not actually be in the film. I'm sure there will be confirmation soon as I doubt Renner would turn down the film considering it's right up his alley.
It's not surprising as Renner is co-starring alongside Tom Cruise in Mission Impossible: Ghost Protocol with the assumption he'll take over the franchise for Cruise. He's also lined up a few films with Marvel Studios playing Hawkeye in The Avengers, a Hawkeye spin-off and other Marvel films. It doesn't hurt that Jeremy has international appeal and gained two Oscar nominations in the last two years for his great work in the Hurt Locker and The Town. He's currently finishing up Hansel & Gretel: Witch Hunters before starting Avengers.