The Family Research Council organizes the Values Voters Summit. Below are the listed of confirmed and invited speakers as it appears on their website as of right now.
But if use the Google Cache and look at their website as of June 19, 2009, you will see that South Carolina Governor Mark Sanford was originally included (second to last row, third column).
Maybe they should have kept him on the list, to hear a remorseful man looking for redemption?