I think same sex marriage is great! There is no shortage of people in this country so at least they will not be adding to the problem in that regard.
As far as the Christian stance on this; let it go. You believe in a book you don't take seriously (you pick and choose what you feel is God's true word), so why get bent out of shape because two dudes (or dude-ettes) love each other and want a legal commitment. As long as you get to your "Heaven", why hinder other peoples lives. Oh, that's right, Christians as a general rule are hypocrites.