OK, I made it all the way through the first transcript. Some observations:
* Roberts, Scalia, and Alito seemed dead set against. I can't imagine them voting in favor of same sex marriage. Sotomeyer, Breyer, Ginsburg, and Kagen all made arguments in favor and I'd expect them to vote that way. Kennedy seemed on the fence. He didn't like the respondent's argument about the states compelling interest in preventing same-sex marriage, but he also didn't like the court redefining marriage.
* Was Justice Thomas even THERE???
* The first attorney arguing in favor, Mary Bonauto, seemed tentative and scattershot. I wasn't impressed with her responses. Solicitor General Verilli was much more polished. The attorney for the respondents also didn't impress. He spent too much time talking about how same-sex marriage will erode the bond between married couples and their kids long after it became obvious that only hurt his arguments.
Still, I don't think this is quite the slam dunk everyone thinks it is. It will come down to whether Justice Kennedy is comfortable imposing the court's will on the states, something he seemed somewhat uncomfortable with at times.