I'll probably be flamed for this but... not everyone who has issues with gay marriage is a bigot, religious nutjob, or homophobe.
On a civil liberties standpoint I'm all for gay marriage. Let them confess their love, show affection in public, have a wedding ceremony, fuck like rabbits, whatever they want... That doesn't bother me one bit.
However, I fail to see how offering gay couples the financial benefits of official marriage benefits society as a whole. It was my understanding that the entire reason these benefits exist was to foster the creation of a financial environment where a couple can begin raising children. Gay couples can indeed raise children, but some quick stats from Wikipedia show that only around 20% of them do raise children, with the majority of those children currently coming from prior hetero marriages; Marriages which I doubt would have come about if their sexual orientation was more publicly acceptable. Conversely, only around 20% of heterosexual couples do NOT raise children... which kind of tells me that the institution of marriage as a financial status is working as intended.
I say let them get "married" but do not allow them to share employment benefits, claim each other as dependants, transfer tax credits, ect, until either the specific couple actually does support children, or the percentage of gay couples raising children comes in line with hetero marriages.
By offering these benefits to those gay couples who have no intention of raising children, the world is saying those two people are more valuable to society than two similarly employed single people, and I just don't see why that would be. I also feel the same way about hetero couples in their 40's + who obviously do not intend to raise children.