Apparently the Wachowskis (and Tom Tykwer, and maybe Natalie Portman) have other ideas. (Turns out that story is a year and a half old.) Here's the latest:
Tom Hanks, Natalie Portman, James McAvoy, Halle Berry and Ian McKellen are now attached to Tom Tykwer’e potential adaptation of David Mitchell’s dense novel “Cloud Atlas,” a source tells The Playlist. All of the above talent had been rumored to be circling the project, though now it seems to be “official.”
Wikipedia has a decent summary of the book's structure and stories.