On this topic I am going through a similar situation with my wife where two weeks ago she had told me that she would never divorce me and was basically committed to me, and after a bad weekend that started 10 days ago she since moved out of the apartment and into a new apartment I don't have the address to, and told me not to contact her, or her friends or family, and she was going to divorce me. From what other people including my former landlady has described she has been completely beside herself with fear and anxiety and does not appear to be someone calculating to go sleep with some guy.
She's basically told me that she can no longer stand to be with me due to lack of trust, me never loving her, being afraid of me due to my anger, the typical WAW laundry list. She is currently filing D paperwork, but has at least stopped being so visibly furious and has become more polite now that I am talking to her about the D and how to move forward. I think that has been my 180, to embrace this as opposed to running from it.
I spoke with a DB coach who told me to not get in the way of the D and to even "partner" with her in the process. He told me that the marriage between my W and I is gone, and my best bet would basically be to work on things after the D by being her friend and see if she comes back around when she eventually realizes I can change and I am not a bad guy.
I never would have said this a few months ago, but you need to be supportive of her with whatever decision she is making (other than an affair) and give her space/time to think and calm down.
I keep looking for data/threads on numbers of walk away wives who decide to come back and reconcile, and the timetables for this, and can't seem to find anything.
T 10 years, M 4 years, both 28 years old 7/3/2013 - W wanted D, we attempted to reconcile 7/20/2013 - discovered W's EA, attempted to reconcile 8/24/2013 - W told me she wanted D, filed papers