Pastors are going to have to insulate themselves from the possibility of lawsuits. I'm not sure if anyone has heard of the "Marriage Pledge". Essentially, pastors are refusing to function as agents of the state and are conducting purely "Christian" marriages and allowing couples to seek civil recognition on their own. Part of the pledge reads:
"Therefore, in our roles as Christian ministers, we, the undersigned, commit ourselves to disengaging civil and Christian marriage in the performance of our pastoral duties. We will no longer serve as agents of the state in marriage. We will no longer sign government-provided marriage certificates. We will ask couples to seek civil marriage separately from their church-related vows and blessings. We will preside only at those weddings that seek to establish a Christian marriage in accord with the principles articulated and lived out from the beginning of the Church’s life."
This is more akin to the Quaker view of marriage. Here are some excerpts from "Faith and Practice": "Quaker Marriage Procedure"...
"Marriage is a sacred commitment of two people to love one another in faithful partnership with the expectation that the relationship will mature and be mutually enriching. Friends know that marriage depends on the inner experiences of the couple who marry and not on any external service or words. Thus, the ceremony in which the couple enter into this commitment is performed by the couple alone, in the presence of God, the families, and the worshiping community. Both the solemnity and the joy of the occasion are enhanced by its simplicity."
"While most Friends’ marriage ceremonies conform to civil law, couples who do not want, or are not eligible to contract a legal marriage occasionally ask for a ceremony of commitment or a wedding under the care of the Meeting. The Religious Society of Friends has long asserted its freedom to conduct under divine leading marriage ceremonies not conforming to civil law."
This is the best way for pastors to insulate themselves from the coming onslaught of lawsuits and litigation from the gay rights movement. For those interested, here's the pledge in it's entirety:
http://www.firstthings.com/marriage-pledge