I can't think of any way to distinguish the reasoning in Loving from applying to SSM, as well. I can't see how Prop 8 will survive. The only way that this could not be settled is if they just deny standing and kick it down the road. In which case, Walker's decision stands, as you said. But there's no cause for legal limbo. No more appeals will be available. The only real result of not simply striking down Prop 8 is to avoid making a ruling on the level of scrutiny that SSM will enjoy. Walker's ruling doesn't afford it strict scrutiny, but rather says that an SSM ban fails to meet rational basis. Which means that enforcing SSM protections in other states will be more difficult. California will be pro SSM no matter what they rule, unless they declare that SSM has no constitutional protections at all and uphold Prop 8. This is astoundingly unlikely, though. Marriage in general and SS conduct were both previously protected by the supreme court. The real question is how much of a roadblock will exist towards legal protections in the rest of the country. Though full faith and credit will mean that a SSM performed in any state is binding in every state. Generally, unless the court goes full bigot, SSM is here to stay.
Race is looked at under strict scrutiny. It could very easily be ruled that strict scrutiny is not applicable for SSM, that intermediate or rational basis is correct. Under both intermediate and rational basis, it is possible the court could rule for Prop 8. Unlikely, but possible.
If the court rules that the petitoners lack standing, that would dump it back to Judge Walker's decision,
and the stay on that decision would be in place while petitioners with standing where looked for.
If the court DIGs it(rules that it should not have accepted to hear the case), then it goes back to the appeal court, and again the stay would be in effect while more matters are ironed out(I do not entirely understand exactly the details here, the legalese went over my head).
There are a number of routes with less than ideal outcomes for those of us who support SSM. Scalia in the oral arguments for the Windsor case questioned the research into the effects of SSM, and while unlikely, his arguments along those lines in Perry could sway Kennedy and a conservative coalition gives exactly the ruling we do not want. More than likely however the court will punt the case with either a lack of standing or a DIG. Neither is ideal for SSM supporters.
And in the interest of fairness and honesty, various places are reporting as you claim about lack of standing. I am basing how it would turn out on articles from SCOTUSblog, which I think is the most reliable source. The reality is that there is some question how it would play out.
Even in Windsor, the court could rule that the house does not have standing to defend the law, which would result in Windsor getting her money, but DOMA still being the law. There are lots of possible negative outcomes. Remember, based on oral arguments, almost every expert assumed that ACA would be overturned by the supreme court, when in fact it was upheld, and Roberts voting in favor of it. Predicting SCOTUS is not a safe thing to do.
