The Human Rights Campaign has a "special edition homepage" right now with a slideshow of wedding pictures from same-sex couples married in Massachusetts. I find these images, like the pictures from San Francisco, incredibly moving. I didn't grow up dreaming of a wedding dress, or ever thinking I'd be married -- I think for two reasons: because my parents (good 50s intellectual atheists) had only a civil ceremony, and there were no pictures, no white dress, no wedding ideology; and because I knew pretty early on that I wasn't interested in men, so that ruled out weddings too. The games my friends and I played mostly involved alien invasions, orphanages, and schools -- I can't remember ever playing at getting married, or having dolls that married, or anything like that.
So it's a real shift in my own perceptions to imagine that my partner and I could marry, and have that be significant in a way that isn't just private, and personal, but also institutional, and legal. Commitment ceremonies are absolutely important; there is tremendous symbolic significance in having your friends and relations support and acknowledge your primary relationship. But it would also be really significant to be able to put my partner on my health insurance as my spouse.
Part of what I find so encouraging is that gay and lesbian people are now visible in general American culture in ways that 15 or 20 years ago could never have been imagined. My gf and I watched part of the democratic candidate debates last year and it was surprisingly powerful to hear the candidates talking about gay marriage -- not because of what they said -- since most of them were sort of wishy-washy on the subject -- but that we were being discussed at all. Civil rights are hard to come by if your existence isn't even acknowledged. Same-sex marriage is one way to begin making the existence of lesbian and gay people more commonly recognized and accepted.