I am not optimistic about the challenge to Prop 8. Today, the California Supreme Court voted 6-1 to review the validity of Prop 8. The sole dissenting judge was Justice Kennard. The press release is here.
As you will recall, the California Marriage Cases were decided by a bare 4-3 majority. Justice Kennard was in the majority there, along with Chief Justice George, and Justices Moreno and Werdegar. (Justices Chin, Corrigan and Baxter were in the minority.) (See this Wikipedia article.)
This indicates that Justice Kennard is not inclined to strike down Prop 8 and that she would hold in favor of its constitutionality as an amendment.
So, our only hope is to convince one of the other three justices to switch their votes. Which of them is likely to do so?
Perhaps Justice Chin. As an Asian-American, he might be more willing to listen to structural arguments about equal protection, particularly given the history of discrimination that Asians have faced in California. I hope the petitioners craft their briefs to appeal to him.
Of course, it might still possible to get Justice Kennard to change her mind, and to change other minds. (Wouldn't bet on it though.) In addition, it is necessary to hold the votes of George, Werdegar and Moreno (who is Latino).
Also, Justice Kennard indicated she might be willing to uphold the marriages prior passage of Prop 8. So perhaps not all is lost.
But at this time, I would not bet on the Supreme Court invalidating Prop 8. We must continue to build our movement for an electoral rematch with the right-wing in 2010.