My boyfriend and I are planning on moving in together sometime in the near future, but we don't have any plans on getting married any time soon. I know I'm only 19, but we have our reasons. We've been together for 2 years. Starting in November I will be attending a University in a city called Federal Way which is over 50 miles away from Everett, the city I live in now. I have a decent paying job in Everett and would like to keep it. My boyfriend also might be attending the same school, but if not he will be going to a different one in Seattle - also a ways south of Everett. It would help both of us to live a little closer to the schools - probably somewhere around Seattle (that's about the mid point between Everett and Federal Way). We both could probably afford to live by ourselves, but BARELY. It would be much easier if we had two incomes. Plus, I don't really want to live all by myself. No one else I know is looking for a roomate right now... and I really don't want to become a roomie with someone I've never met before. Sorry for babbeling, I just thought I should explain my reasoning.
So obviously, I don't think it's a bad idea to live together before you're married. But like bnormal said, I'm sure it all depends on the couple.