(The California legislature, which represents the 25% of the state's citizens who describe themselves as "liberal," is trying to overturn that ballot initiative, which passed in 98% of the counties in the state. But I digress.)
I think the decision is based on very questionable reasoning. (How's that for a restrained statement? I could have said it borders on being silly, but I'll hold off for now.) Eugene Volokh analyzes the decision here. I am persuaded that Volokh is right -- this decision will be overturned.
By the way, I encourage everyone to read Volokh's discussion of why Constitutional equal protection arguments are inapplicable to the gay marriage debate. Too many people throw around the words "equal protection" without really understanding the way courts use the concept in Constitutional law.