If you set moral objections aside, this is a bad ruling from a Constitutional point of view. If there had ever bene a Constitutional right to marry someone of the same gender, it would have been already been written there. This is lawmaking by judicial fiat, four judges who think their law degrees and black robes give them the right to impose their views on an unwilling public because they think they’re so much smarter than everybody else.
Amen, fellow Freeper, amen! The job of the judiciary is to decide whether something is in keeping with the Constitution or not. If it isn't, the affair is thrown back to the legislative body with "Sorry. No go. Try (re)writing it another way, then we'll see."
It's function is not to decide, "Yes (or No) regarding this case. And now how's we're ordering you to do it."
Ultra Cliff Notes version of this ruling: “They” use the equal protection clause of the 14th amendment. It is for equal application of the laws. The State Supreme Court decided domestic partnership laws don’t protect certain people as well as marriage laws.