Like someone earlier said, she doesn't need your "permission" to leave. What is her state of mind? Is there any doubt?

My W had her mind made up the day she dropped the bomb and nothing I could say or do would make her change it.

Assuming she's done - for now:
If she does serve you papers, you'll have 30 days to respond.
Get some legal advice. Sit down with W and make thing as amicable as possible - less legal expenses that way.
Do youy have children? - Huge factor.
It's gonna be painful - but it wont kill you

Don't do anything or neglect to do anything that you will regret later. Don't act on emotions, whatever you do.

Me 53 XW 50
M 18 Years +2
S14 D19
Bomb 10-24-10
Served 1-27-11
Mediate 4-21-11
Civil D Final 6-2-11
No church anullment
"A man is not finished when he is defeated, he is finished when he quits."