I think any serious commitment between two people, gay OR straight, to "love, honor, and cherish" one another "till death do us part" should be embraced. There's enough division and dissension in the world these days that splitting hairs over which couples should have the right to enter into legally-sanctioned wedded bliss should be a non-issue.
It wasn't that long ago that it was against the law for biracial couples to marry. The world didn't come to an end when the law was changed. The world won't come to an end, either, after gay marriage is legalized in every state. And it WILL. Sooner than later.