Only been married since last October, so 9 months. I guess you could say we dated for a year before moving in together. Once you're moved in, saying you're dating is odd, since you're together all the time and share a place. So boyfriend/girlfriend living together for three years, then got engaged and then married.
So I guess it doesn't feel that different, seeing as our living situation married is the same as it was for the three previous years living together in sin.
The real changes are that things are far more relaxed. I mean, no expectations in terms of proposing and no wedding planning since it has all already happened. Also, there are the little government perks and the status symbol of having a ring. But yeah, not terribly different.