There are some excellent conversations going on here that could fill three or four different threads, each with it's own theme; homosexuality, polygamy, the origin of sin, the theology of free choice, etc. etc.
I am not against homosexuality any more than I am ready to be against someone who throws an angry fit, tells a lie, spends their life living as a victim or has negative attitudes. But I can not deny that the death of Christ upon the Cross was to set me, and anyone else who chooses to accept it, free from all the things that bind us in life. Our Lord's death was not only (may I even say was not mostly) about paying the due price for our sins, but was about a reconciliation with the Father; a returning to the fullness of relationship with God. I'm not saying the price was not to pay for our sin, but that the motive was to be able to welcome us home.
I can not even begin to imagine that this fullness of relationship with One who calls Himself such things as Love, Truth, Understanding, Holy, Righteous, Creator, Father, Healer (an impossible list to complete) could include such things as remaining a liar, a thief, a bigot or a homosexual.
In a loving and honest parent/child relationship, lies, theft and all of these other things have to disappear. The Law actually reveals His character and His love for us, just as your rules and expectations for your children reflect your character and love for them (or lack of as the case may be for many). Once grown and mature the rules are no longer needed to be laid down because they have simply become our character and reflect our loving relationship with each other.
The Law of the Old Testament was never, ever in any way changed by Jesus. If He broke one single one of the OT Laws (the very Law of God) He could not have died a sinless death and was not the Messiah. What He changed was the Traditions of Man (called the Oral Law) which had come out of the different sects misunderstanding its true purpose and meaning. (Mat 15:3).
But I fail to address the original question of this thread:
Should we hope that the Supreme Court strikes it down which could put biblical prouncements about end times at odds with the decision, or should we hope that there's a majority vote for it, thereby confirming Scripture.
I personally belief (and accept that many may not agree) that our role in prayer is never to change God's will or plan; "Thy will be done here on earth as it is..." comes to mind. But I must pray for all to come into alignment with His Word, which can sometimes seem contradictory. I pray that the sanctuary of marriage in accordance to God's Word will remain unchanged by the world's courts (a sanctity which never included same sex marriages, polygamy or divorce Mat 19:8). However, I accept what will ever happen as being part of God's will because, in the end, He is in control of all things.