Boxer Muhammad Ali, left, and his wife, Yolonda Williams, participate in the Opening Ceremony at the 2012 Summer Olympics, Saturday, July 28, 2012, in London. (AP Photo/Cameron Spencer, Pool)

Boxer Muhammad Ali, left, and his wife, Yolonda Williams, participate in the Opening Ceremony at the 2012 Summer Olympics, Saturday, July 28, 2012, in London. (AP Photo/Cameron Spencer, Pool)