A New Jersey judge just ruled that:

Same-sex couples must be allowed to marry in order to obtain equal protection of the law under the New Jersey Constitution.

This is good news, but the logic of the ruling is kind of strange. Some background:

• In 2003, a MA court allowed gay marriage (Goodridge).
• In 2006, a NJ court ruled that ruled that "the State must provide to same-sex couples, on equal terms, the full rights and benefits enjoyed by heterosexual couples." (Lewis) The court gave the state the option of either opening marriage to everyone or creating civil unions, and the state went with the civil unions.
• In June 2013, the supreme court ruled that section 3 of DOMA, which had restricted the federal government's definition of marriage to opposite sex couples, was unconstitutional. (Windsor)

Same-sex couples in states like MA, where they can get married, are now eligible for federal benefits that depend on marriage. There are quite a lot of these, from the Family and Medical Leave Act to immigration to taxes. The federal government has as a whole not extended these to couples with civil unions, which means same-sex couples in NJ weren't eligible for these benefits. The claim in this case was that because NJ was required to provide same-sex couples "the full rights and benefits enjoyed by heterosexual couples" and these couples could only get federal benefits if the state labeled them as "married," the state government needed to allow them to marry.

This claim was accepted by the court, but I'm not sure it should have been. If the division into marriages and civil unions was accepted at the state level, that a separate organization was interpreting the division in a discriminatory way seems to be a problem with that other organization's actions.

Let's look at a related example: the states classify each of their residents by sex. Consider a hypothetical US state where after a lawsuit the court rules that "the State must provide to both sexes, on equal terms, the full rights and benefits enjoyed by either" but does not permit residents to change their official sex classification. Now imagine the federal government started providing additional rights or benefits to one sex: would the state government need to start allowing people to change their sex? Or stop classifying people based on sex? It seems to me that the federal government's use of sex classification in a discriminatory way is the problem, and that while it would be good for the state make these changes they're not required to.

(An alternative argument would be that the whole point of government marriage is classifying couples so that other parties can treat them differently. So if you know people are going to take your classification and use it in a discriminatory way, you need to stop making it. But it doesn't sound like the law works that way.)