** FILE ** Pope Benedict XVI leaves St. Peter's Basilica on a mobile platform at the end of a Mass at the Vatican on Sunday, Oct. 16, 2011. (AP Photo/Gregorio Borgia)

** FILE ** Pope Benedict XVI leaves St. Peter's Basilica on a mobile platform at the end of a Mass at the Vatican on Sunday, Oct. 16, 2011. (AP Photo/Gregorio Borgia)