Hi WUK, I'm so sorry to hear of all the pain you are in. I know from experience that it does get better.
Like your's, my W went into MLC and dropped the bomb on me. I NEVER EVER thought either one of us could ever give up on the other.
And like you guys, we have remained civil friends in our home. In our case it's been 9 months now! I see this as a good thing, it seems like while she is still unhappy, she is no longer placing the blame for it on me.
I hope you are reading up on MLC. If you are, you know this is about HER, not you. She is upset with her life right now, and needs to work this out on her own. Give her plenty of time and space and your marriage may survive. Save yourself first.
As for the marriage bed, yes, I think you need to work your way back there. She's the one who wants out, so she should be the one to leave it, not you. That being said, there's a smart way to go about it. I returned to ours, (and then she left it) and posted about it in my thread in the MLC forum.
If you have any questions I'd be happy to help.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl