SpaceX CEO Elon Musk has made numerous public statements about SpaceX plans to send humans to Mars in the next 10 to 20 years (e.g. see Discovery News and PC Magazine). The most recent statement was at an August 1 meeting of the American Institute of Aeronautics and Astronautics (AIAA) meeting in San Diego. A video of the Q & A session is below.
13-minute video of Q & A session at AIAA meeting with SpaceX CEO Elon Musk, August 1, 1011: