For the past 15 years, Oprah Winfrey repeatedly told her team that production of her daily talk show was only the beginning. “This is the foundation of greater things to come,†she would tell her managers as she developed a dizzying array of partnerships and spin-offs — a venture with Hearst Magazines to produce her own, self-titled publication; new syndicated television shows with life coach Phil McGraw and leading chef Rachael Ray; made-for-TV movies; a reality TV show, The Big Give, for the ABC television network; theatrical film releases such as Beloved and The Great Debaters; the Broadway musical The Color Purple; a retail outlet; and a lucrative $55 million XM Satellite Radio Inc. deal. In the midst of these accomplishments, her team could only reluctantly imagine more greatness.