NBC sports chief Dick Ebersol has resigned, the AP reports. A source said it's because of a contract dispute and has nothing to do with the network's current negotiations to broadcast the Olympics or its merger with Comcast. Ebersol, 63, has been running NBC's sports division since 1989. Before that, he directed late-night programming (as a 28-year-old) and helped create Saturday Night Live with Lorne Michaels. (More Dick Ebersol stories.)