I think we welcome them into our churches without judgment.
At such time that they convert, they should have an Orthodox wedding service.
My wife and I had had a civil marriage before a justice of the peace; in the eyes of the state it made us married. In the eyes of the Orthodox Church, we were not that different from a common law couple. When we converted, our priest married us.
Now, that is as regards catechumens or inquirers. As regards the laws of the various states I think we chould affirm the sanctity of civil marriages, heterodox marriages and the marriages of other religions.
These being between a man and a woman.
If homosexuals need something to preserve inheritance rights, acquire health insurance for a partner, etc. the state should have a civil union status that establishes these things without granting it the sanctity of marriage.
These are just my opinions on the matter.