Love is love, marriage is marriage. Marriage, IMHO, should be a legally-sanctioned union between two people who love and cherish each other.
I don't know that specifying gender would provide the institution of marriage with any more or less strong of a sanction. There are both gay and hetero couples who engage in exactly the same types of behavior, from a loving, stable, long-term relationship to being a couple of abusive rat bastards.
For me, it's all about tolerance and respect for each other. Live and let live. There is nothing that would make a gay marriage any more or less binding than a heterosexual one. I don't see what the problem is.
I think that this does point to a larger problem of societal impingement upon personal liberties, sexual in this case. If sexual preference is hard-wired, who are we as a society to say "Sorry, I know you can't help who you are, but you can't get married to the person that you love unless it's a member of the OPPOSITE sex. Thanks for playing." I don't believe that we have that right, even if we are exercising it. I don't think that something is "wrong" just because it runs counter to someone's belief systems, or what they may or may not think is "gross."
It's an issue of respect. You can't say it's an issue of Christian charity any more, given the Catholic church's views on gay unions. "Love your fellow man, just not in THAT way." Unreal, IMHO.
I'm from Chicago, btw...