Some noteworthy question/comments by Justice Kennedy in the oral argument today:
1. Resisting argument against standing of Prop 8 proponents:
Well, the Chief — the Chief Justice and Justice Kagan have given a proper hypothetical to test your theory. But in this case the proponents, number one, must give their official address, they must pay money, and they must all act in unison under California law. So these five proponents were required at all times to act in unison, so that distinguishes — and to register and to pay money for the — so in that sense it’s different from simply saying any citizen. [pp. 6-7]
[In response to Ted Olson:] But this is not whoever it wants. These are five proponents of — of the measure, and if we were to accept your argument, it would give the State a one-way ratchet. The State could go in and make a defense, maybe a half-hearted defense of the statute, and — and then when the statute is held invalid, simply — simply leave. On the other hand, if — if the State loses, the State can appeal. So this is a one-way ratchet as it favors the State, and allows governors and other constitutional officers in different States to thwart the initiative process. [p. 29]
2. On competing harms:
I — I think there’s -there’s substantial — that there’s substance to the point that sociological information is new. We have five years of information to weigh against 2,000 years of history or more.
On the other hand, there is an immediate legal injury or legal — what could be a legal injury, and that’s the voice of these children. There are some 40,000 children in California, according to the Red Brief, that live with same-sex parents, and they want their parents to have full recognition and full status. The voice of those children is important in this case, don’t you think? [p. 21]
[To Olson:] The problem — the problem with the case is that you’re really asking, particularly because of the sociological evidence you cite, for us to go into uncharted waters, and you can play with that metaphor, there’s a wonderful destination, it is a cliff. Whatever that was.
But you’re — you’re doing so in a — in a case where the opinion is very narrow. Basically that once the State goes halfway, it has to go all the way or 70 percent of the way, and you’re doing so in a case where there’s a substantial question on -on standing. I just wonder if — if the case was properly granted. [47-48]
3. Resisting Reinhardt’s (purportedly) narrow rationale (p. 42):
The rationale of the Ninth Circuit was much more narrow. It basically said that California, which has been more generous, more open to protecting same-sex couples than almost any State in the Union, just didn’t go far enough, and it’s being penalized for not going far enough. That’s a very odd rationale on which to sustain this opinion.
4. Disputing Ted Olson’s claim that invalidating traditional marriage laws would be as modest a step as invalidating anti-miscegenation laws was (p. 49):
It [traditional marriage without racial restrictions] was hundreds of years old in the common law countries. This [anti-miscegenation laws] was new to the United States.
5. On possibly dismissing case (as I read it, for reasons other than alleged lack of standing):
I just wonder if — if the case was properly granted. 
[On Cooper’s rebuttal:] You might address why you think we should take and decide this case. 
Update: I’ve modified/clarified item 4.