Today's decision is not about the right to marry technically - and in this case, technically is all that really matters.
Technically, this decision is about whether or not Proposition 8 on November's ballot was constitutional. Whether it was a revision or an amendment. If it was a revision, then the referendum process is not sufficient. This decision isn't about same sex marriage but about the referendum/initiative process in California - even though it is deciding the fates of millions of California couples.
Arguments made on both sides were not about whether marriage should be allowed but whether the people of the state of California get to decide on certain rights and how that should work -- whether by legislation or by referendum.
We'll know in about 2 hours what the Supreme Court decides. I hope people remain non-violent if the court does not decide to overturn the amendment. While anger is important and useful, violence never is.