Here are a couple of links to discussions of the topic at hand on Fresh Air with Terry Gross. My apologies if these have been brought up already. I haven't read this whole thread. But I did find these interviews enlightening. I found the nun to be more in tune with my views than the Bishop. But I am not a Catholic so I don't really have a direct personal interest in the debate.

http://www.npr.org/2012/07/17/156858223/an-american-nun-responds-to-vatican-condemnation

http://www.npr.org/2012/07/25/157356092/bishop-explains-vaticans-criticism-of-u-s-nuns