With New York becoming the sixth state to allow same-sex couples to marry (in addition to Connecticut, Iowa, Massachusetts, New Hampshire, Vermont, plus Washington, D.C.), and adding the seven states that currently allow marriage-equivalent civil unions for same-sex couples (California, Hawaii, Illinois, Nevada, New Jersey, Oregon, Washington), plus the four states that have limited civil unions or domestic partnerships (Colorado, Maine, Maryland, Wisconsin), I see trouble for the 30 states whose constitutions or laws ban any legal form of same-sex coupling.
With many American gay couples now marrying, adopting children and creating wholesome families, and then doing what American families do moving Americans' sense of justice and fair play will increasingly scorn the situation where a married New York same-sex family of four moves to Utah (or Mississippi or Alabama) and presto! they're no longer married! Soon the federal Defense of Marriage Act, which says states don't have to recognize marriages in other states, will fall under the wrongness of its mean-spirited consequences.
Even "pro-family" Utah will have to adopt the stance of Maryland and New Mexico they don't permit same-sex marriage ceremonies, but they recognize marriages performed in other states. So why wait? Have a heart. Do that now!