Appeals are not a last-resort, then are a next-resort. 8^) If you aren't pleased by a decision, and you have enough money and are angry enough, you can almost always find a way to appeal the decision. In this case, though the ruling is only in effect in California, it's national politics we're talking about, so there is plenty of interest and plenty of money.
The gay marriage question will eventually be solved once and for all by the US Supreme Court, and until then it will continue to be fought. There are many precedents for this. The Supreme Court banned laws against miscegenation (inter-racial marriage), which was just as controversial in its day as gay marriage is today. But once the Court decided, it was settled once and for all. Same with school segregation. Same with 'sodomy laws'.
And even abortion! The Supreme Court decided that with Roe v. Wade in 1973. Republicans have been promising to overturn Roe v. Wade for 30 years now but haven't even really tried because they know it's impossible.
And gay marriage will be like that. It will be a major political issue until then. Maybe not -this- Supreme Court, but sooner than you might think.