Retrouvaille is an intense marriage encounter weekend for couples on the verge of divorce. I would highly recommend it. The weekend is mostly about how to properly communicate.
My W and I went and she really opened up. However, after that weekend she claimed that although I was her best friend she did not have that feeling of love for me.
It is sponsered by the catholic church, but I would say roughly 50% of the couples in our weekend (or 1/2 of the 35 couples in total) were not catholic and there is no push of religion at all. They claim to have a 70-80% success rate of saving marriages. My W thought it would be good if couples actually attended before they got married.
As far as MC, as suggested by others, perhaps go by yourself first and the next time she brings up divorce, suggest again going to MC. Just a thought, but in my opinion if there are EA's and/or PA's it becomes more difficult.
Me: 48 Ex-W: 45 M: Nov '96, together since Oct 93 Bomb: on 10-yr anni - Nov '06 OM Separated: mid-Feb '07 Divorced mid-July '08 One daughter - 28 XW living w/OM