It’s important to note that Justice Kennard voted to deny cert in the case AND made note that she would be interested in a challenge that dealt just with question three (what to do with the licenses that were issued prior to its passing).
Justice Kennard was in the majority decision on the gay marriage case. The fact that she specifically noted that she’d be interested in question three only is, I think, a good sign for pro-Prop. 8 position. Not only is she signaling her disinterest in the challenges, but she is also kind of making it clear that her reason for doing so has nothing to do with letting the issue percolate in the lower courts first, because she seems willing to hear argument over what should be done with the previous licenses right now. That suggests that she’ll be a vote to uphold Proposition 8.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
I think it's good that the California Supreme Court agreed to decide the case, and get it resolved sooner rather than the later. It's important to know what the law is on this, especially given the likelihood that Prop. 8 invalidates same-sex marriages that had been entered into after the earlier court decision but before Prop. 8's enactment. I also think that the California Supreme Court will reject the state constitutional challenges to Prop. 8, and conclude that Prop. 8 amends the state constitution in a way that supersedes the court's interpretation of the preexisting constitutional provisions. (Here's my response to the "unconstitutional revision" argument, but I think the other arguments I've heard about are unlikely to prevail, either.)
Of course, Prop. 8 can't overrule any federal barriers to its enactment. I think there are no such federal barriers, but it's not as clear to me that the California Supreme Court will agree. [UPDATE: After a correction from Rick Hasen, I now think that the California Supreme Court is highly unlikely to reach this question, given the issues that it ordered briefed and argued.] And if the California Supreme Court invalidates Prop. 8 on federal constitutional grounds, for instance on the grounds that it's precluded by the Romer v. Evans decision or that the federal constitution bars discrimination against same-sex marriages, then the issue will be reviewable by the U.S. Supreme Court (and I think the U.S. Supreme Court will indeed agree to review it).
UPDATE: Rick Hasen (Election Law Blog) reports that, contrary to my suggestion, "it does not appear that an argument that the measure violates the federal constitutional guarantee of equal protection is fairly before the court in its review." Reviewing the issues listed in the court's order granting a hearing leads me to think that Rick is likely right.
Rick also says, "It is also noteworthy that the California Supreme Court denied a stay request pending briefing in this case, with only Justice Moreno voting to grant a stay. That is some indication, though not necessarily a very strong one, that the court will vote to uphold Prop. 8 (the reason is that one of the factors in determining the grant of a stay is likelihood of success on the merits)."
It appears likely the Court will uphold it. A stay is usually granted when success is probable on the merits. Which of course, was NOT granted today. Volokh's reading, I think is a persuasive one.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus