Jbongio --
What you see as deterioration, I see as progress. Painful nonetheless, but definitive steps toward resolution. Remember that we don't grow or learn life's lessons through the happy times, but only through the times of pain, sorrow, and heartbreak. You're growing throughout all of this and your W needs to be there too. Once the fantasy world starts to collapse, real introspection and advancement can take place...and not before.
What have you really learned from the OMW? The truth? Only as she sees it. Only what she's been fed by the OM: a liar and a cheater. Don't mean to dampen your spirits (well, maybe I do!), but you must see this piece in context. Under normal circumstances, I'd be jumping up and down for you, but I wouldn't take this highly questionable third-hand info as gospel truth for any amount of money. I'm not saying this can't go down this way, just that your sources are suspect. Don't assume = Rule #1.
Let's say what you've told us really will happen. It at least would explain your W's panicky contacts with you and her obviously unsteady emotions--she's worried. Four nasty phone calls to you and all telling you that you're ruining everything! Let's get real! She's running scared--a good thing!
I know it hurts to be on the receiving end of those diatribes, from anyone not to mention one's spouse. So...don't listen to her when she's like that (and expect more "like that's" as this falls apart). Just gently end the conversation. Protect yourself and your emotions first.
Let's see if this NC letter to your W really happens. I'm very doubtful and mistrustful with it but it is possible. I'm even sceptical enough to suggest that such a letter easily could be all for "show" and that it's simply a carrot put forth to take the pressure off with both OMW and you. We'll bide our time and keep our eyes open, OK? Not at all wild about it being sent email; whatever happened to good, old-fashioned snail mail? Maybe that's a generational thing?
Since you've asked for it, my advice would be to sit tight and let her come to you. You don't want her back in your life simply because she couldn't have someone else. You don't want her back angry at you because you've "ruined" her chances for happiness with OM. You don't want to settle for crumbs.
Let W handle the OM's apartment stuff herself. If OM in fact is never returning, he'll find some way of getting his things out and one of them is W! She can't/won't stay there without him, right? What will she do? Where will she go? You don't know at this point. So, you hang loose and see where this all is going. She knows where to find you. Be an observer, not a participant at this point.
What's planned for Thursday? This email NC letter? Don't necessarily expect "action" or fallout from this immediately, even if Thursday is the day. BTW, one last point: having her move back in with you without addressing and attempting to solve these problems guarantees that you both will be back in this same boat within a very short time frame. It is imperative that boundaries and understandings be established and adhered to. Otherwise, you're both in for a repeat performance.
I hope it all comes together for you. You know that I wish you well. Keep us in the loop...
Ammon