Read the opinion (I did). The judge isn't "making law" here. He's applying about 50 years of well-established legal precedent to the facts of the case before him. In Loving v. Virginia the Supreme Court identified marriage as a fundamental Constitutional right. As a fundamental right, states must make that right equally available to all citizens, under the 14th amendment. The Loving court struck down laws prohibiting marriages between people of different races.
In this case, the judge applied the same principles and held that prohibiting same sex marriage impermissibly infringes on the right to marry on the basis of gender. The state was given the chance to argue to the court an important governmental interest that would be advanced by the prohibition. The judge ruled that the evidence of such an interest was insufficient to justify the intrusion on the Constitutional rights of same sex couples.
There was nothing groundbreaking about the legal reasoning. It was a quite conventional application of existing law to the facts before the court. Arguably, waiting for legislative recognition of same-sex marriage is LESS appropriate in this situation in a Constitutional Republic, because legally speaking, there shouldn't be anything there for the legislature to confer - marriage is a fundamental Constitutional right, and therefore already belonged to same sex couples. The court case was simply necessary to compel the state to recognize a right that already existed.
I think the most groundbreaking thing they said was that gay and lesbian couples clearly fall under strict scrutiny, which courts in the past have been hesitant to do and which makes taking away their rights (i.e., not letting them get married) much more difficult. They're basically treating sexual orientation the same way you would treat any other immutable characteristic. This really says a lot and is a major step in the right direction. The question is, how far will it go?
