Other states would not immediately recognize Calif. same sex marriage if the court ruled that way. However, those people will go back to their home states and file lawsuits in those states to try to force other states to recognize same sex marriage from other states. And eventually they want to go to federal court and challenge the Defense of Marriage Act.
But didn't one state court, (and I want to say New York), decide against a similar lawsuit brought by a lesbian couple that was married in Massachusetts?
Well, it doesn't really matter, because we all know what the agenda is, sad to say.