The Supreme Court ruling seems to have emboldened campaigners for gay marriage here in Europe. The European Commission vice-President, Franz Timmermans, gave a speech the other day in which he said the Commission should try to get all EU member states to accept same-sex marriage.
Now, the commission doesn't actually have the power to do this, since marriage law is explicitly preserved for national governments rather than the EU, but his creative approach is to push it as a matter of freedom of movement. If a gay couple get married in France, and then move to Italy, their marriage would not be recognised. If they have a child, then only one of them would be recognised as a guardian under Italian law. Timmermans argues that this would effectively limit their freedom of movement, which is a legally guaranteed right.
Now I'm not sure this would stand up in court, but based on the timing, I can't help but feel he's been inspired by the American example.