To add to this, I know many "married" people, myself included, who are permanently separated with no intention of reconciliation, but who are not legally divorced. My ex and I did not have an acrimonious "divorce" and money was never an issue between us, but the mess and expense of divorce don't seem worth it to us as long as we both trust each other (which we do).
I'm sure we'll eventually get divorced once one of us gets a long term partner, but I do think the trend for avoiding the legal system as long as possible is here to stay. I know one couple (or ex-couple, rather) that has been separated for over 5 years now.