I can't believe I missed all this while I was in Tampa...poor NoHall!
I think NoHall and I had a great conversation on this back in the spring. That conversation was based on the "threat to marriage' argument, and we agreed that of the many threats to marriage, gay marriage doesn't even rank. Things that do rank -- divorce; societal acceptance of things like starter marriages, trophy wives, mistresses, etc.
My point was that the government doesn't convey 'sanctity' on a marriage -- it is a contract between two people, and any sanctity is conveyed by the people involved and their personal beliefs. the government can't help nor harm the religious institution of marriage. Government does have a responsibility to give all an equal ability to enter into a beneficial social/family arrangement that fits their needs.
Single people do get a raw deal. It's cheaper and easier to live in pairs. Single people pay more for insurance, loans, and pay a higher tax rate. Their co-workers also expect them to work for less money and take the bulk of the overtime since they don't have sick kids or recitals to attend.
I worked for a company that as a rule didn't hire single people because they were 'too transient' and created to many office dramas -- this was explained to me by the married jerk boss who sent me suggestive emails and constantly wanted to tell me about his wife who didn't understand him and neglected him and put all her energy into the kids. He'd then suggest my best friend and I bring our bikinis over and try out his hot tub while uncaring wife was out of town. If you asked his thoughts on gay marriage, though -- that was a threat to the sanctity of his marriage and next we'd want to make bestiality legal and let people marry giraffes.
Civil unions, marriage -- I don't care what the government calls it as long as the same protections are extended to everyone. I also think that if I have a best friend and don't have the prospect of getting married because I'm too finicky or elect to grow my toenails into massive curling talons, I should be able to make that person my next of kin without having anything sexual involved...because my mother is a looney bird and I have no children, and sometimes friends become family after a time.