Saying this is an issue of a state constitution is a joke. The decision was based on phrases included in the U.S. Constitution and pretty much every state constitution -- "Equal Protection" and "Due Process" It cited many federal cases, especially Lawrence vs. Texas. It even mentioned Canada's legalization of gay marriage. It was an in-your-face decision that was a clear violation of the guarantee clause. The people of Mass. cannot respond for two years. They are unrepresented. Gay marriage supporters are getting it both ways, they are arguing on constitutional grounds -- wording in the US Constitution -- yet they are claiming marriage a state issue. It can't be both.
In truth, it's neither. Marriage is a legal issue, already pre-defined. For a court to change the meaning of the words that delineate the law is to change the law itself -- Something that the courts are not empowered to do.
If this matter stands, the rule of law will be just an empty phrase and will have no practical meaning or use. Once the court succeeds in subverting this principle with impunity, the bedrock of our constitution which holds all men of good will in check will be destroyed. The court would be well-advised to consider the consequences.