EXCLUSIVE: CAA lost the longtime top client in late December. And now I’ve learned that Oprah Winfrey has signed with WME‘s Ari Emanuel and Rick Rosen and a team of agents. The big signing comes after Oprah and her cable network OWN scored 3.2 million viewers for her confessional sit-down with disgraced doper Lance Armstrong. I understand today’s move culminates a long slow wooing by the agency, the same kind that WME has done with Dick Wolf (successfully) and Shonda Rhimes (unsuccessfully, for the moment), and some other key TV creators and producers. Winfrey had been a very important client for CAA. Among other things, the agency put together her deal with Discovery Communications for OWN: The Oprah Winfrey Network. But Oprah isn’t an easy client by any means.