As of today, New Mexico has marriage equality thanks to its (unanimous) state Supreme Court. Previously, New Mexico, thanks to a divided legislature, had no laws whatsoever about marriage equality. That made New Mexico unique in the country.
This decision was not entirely unexpected. Oral argument suggested which way the Justices were leaning and an earlier decision against a (I think) photographer who refused to photograph a ceremony for a same-sex couple was a tacit acknowledgement that the Court believed in protecting the rights of New Mexico’s LGBT minority. It is also important to remember that it was the county clerks who forced this case in the first place.
It is important to recognize that this case is yet another direct result of Windsor–and yet another example proving that Windsor is perhaps the second most important civil rights case in US history after Brown v. Board of Education. Once the US Supreme Court handed down Windsor, the clerk of Santa Ana county began issuing marriage licenses. Other clerks followed suit (either based their own interpretation or by court order). All the clerks asked the state Supreme Court for review.
Prior to November 2012, six states (and DC) offered marriage equality to same-sex couples. Now there are 17.
In truth, it only gets harder from here. Most of the remaining states have a constitutional amendment of some kind banning marriage equality. Only Pennsylvania, Wyoming, West Virginia, and Indiana have laws rather than constitutional amendments that ban same-sex marriage and none of those states would make for an easy legislative victory. (In Indiana, activists have their hands full trying to prevent a constitutional amendment to ban same-sex marriage.) Oregon has a ballot initiative next May to overturn its amendment, but for the most part now it is time for the federal courts to get involved.
It is also important to recognize that 21 states (and DC) offer marriage, civil unions, or domestic partnerships to same-sex couples. As the federal courts decide these cases, that number will grow. Those who oppose marriage equality no longer have federal legislative options at their command thanks to Windsor. Which means that to stop same-sex marriages federally, they need two-thirds of both Houses of Congress and three-quarters of the states to adopt it. That ship has sailed. New Mexico is the latest proof.