I ask this in all seriousness, as a married, heterosexual man:
Why would any other straight person give a rat's ass whether gay people get married or not? I mean - I've been married for almost nine years, and if some other group of women and men is so eager to join THIS club, I say, "more power to 'em". Not that I'm not happy being married, but really, is having it all legal and official making YOUR life some kind of heaven on Earth? (to Jessica Alba's husband, you ba$tard, don't answer that).
It's no skin off my nose if two lesbians get married - it's not like they were ever potential dates for me anyway (even if I wasn't already married). Really - are there people so insecure in their own sexuality that they're "terrified" of the idea that two dudes might tie the knot?
Geesh... let 'em all get married, so they too can experience the amazing joy of married life </sarcasm>. Why is this even an issue, unless some religious nut-cases are going off about the bible again (in which case - aren't you meant to be out chasing Darwin or something?)
Last point - I keep hearing about this "sacred" institution. In a country with a 45% divorce rate... um, yah.. I can see just how "sacred" it is, this holy covenant of state-sanctioned, IRS-approved living arrangements. *rolls eyes*