The Ninth Circuit Court of Appeals decision applies only in California, according to its terms. But by striking down California's Proposition 8, the voter-approved anti-gay marriage initiative, the court put the issue of gay marriage bans squarely before the U.S. Supreme Court.
North Carolina has an anti-gay marriage statute, and we'll vote in May on an amendment to the state constitution banning gay marriages and also civil unions between same-sex partners.
However, a state — even in its constitution — can't discriminate against citizens in a way the U.S. Supreme Court has declared unconstitutional under the 14th Amendment to the federal constitution. That's what the Civil War was all about: States can't violate fundamental rights.
Some day, we'll think about these gay marriage bans the same way we think about the Dred Scott decision.
Talking Points Memo posted a handy map of states and their status re: gay marriage, civil unions & equal rights.