The government needs to get out of the marrying business. Marriage should be a religious arrangement. Continuous lengthy cohabitation should, absent a contract to the contrary, be a default contract laying out certain rights as would a common-law marriage. Apart from that, the government should have nothing to say.
The controversy over gay marriage should be a lesson to everyone who wants the government to do more in society. Every disagreement comes a reason for political unrest.
The more government interference in civil society, the less civilized and the less peaceful the society.