U.S. mobile content aggregator and social network Mixxer has announced a change of leadership, with Bill Bryant stepping down as CEO (but remaining as a board member) to be replaced by John Dearborn. Dearborn was most recently general manager and senior vice president of American Greetings Interactive. The company also appointed two new members to the board of directors: David Carlick, managing director at VantagePoint Venture Partners, former director of Ask Jeeves and former chairman of Intermix Media, majority owners of MySpace, and marketing expert Mark Metcalfe, CEO of Overton’s with 15 years experience building direct marketing companies.