For me, personally, if I were to have 2 weddings, other people could think what they want about which is the real one, but it wouldn't change what I considered to be the real deal. If it's not your wedding, then who cares? It's about the people getting married, not you.
If I considered my "real" wedding to involve no paperwork what-so-ever, with a goat standing before me and my SO while we dance around in buckets of paint wearing marching band outfits, then that is it. If that is the meaningful moment when we consider ourselves bound together for life, then that's all that matters. Other people might not consider that the "real" wedding, but rather the legal mumbo jumbo, but those people aren't the ones in the relationship, and therefore their opinions just don't matter.
The signing of a piece of paper doesn't change how people feel about one another and certainly doesn't have to mean that it's a "wedding". Are you married at that point? In the eyes of the law, yes. But many people find the ceremony and the party, and the cake cutting and the boquet toss to be the wedding, and the point at which they are married.
As for same-sex marriage, suffice it to say that my stance on it is that it's a rights and legal issue, not a "real wedding"/"fake wedding" issue. It's about people being able to expect the same rights and treatment as everyone else. Even though they may not have the certificate, I would still think some same-sex couples would take issue with some one saying that their ceremony wasn't a "real" wedding.