It's really good that the voters said yes to marriage equality here in Washington State. The cases that are now coming up to the Supreme Court are about constitutional rights versus the states where voters voted against gay marriage. For instance in California, where voters opposed marriage equality by supporting California Proposition 8 several years ago. Now Proposition 8 is being tested in the courts, but no matter how the Supreme Court rules, in this case, Washington State's voter approved law is still safe, as far as I know. Hope the court rules in favor of tossing out California's anti gay marriage Proposition for the states that weren't as fortunate at the ballot box.
States where voters approved gay marriage in 2012 are Washington, Maine and Maryland.
In Minnesota, voters turned down a proposed constitutional amendment against gay marriage. Attitudes of voters seem to be changing fairly quickly on the gay marriage issue. Maybe California will take another vote someday, but in the meantime, that case is before the Supreme Court.