Regardless of the "religious" and morality rhetoric which many want to wrap around the "gay" marriage debate, the real issues are the legal issues which define the rights and obligatiosn of a "marriage."
Calling a "gay marriage" a "Civil Union" would work if in deed that code of law were exactly the same as the code of law defining marriage....law makers don't do that. Civil Unions do not grant the same legal rights as a "marriage."
Perhaps it's time that Marriage laws are removed altogether, and people create their own civil contracts. This way, they can live how ever they want, and agree to whatever rules suit their way of life and beliefs.
Abolish the federal marriage tax penalty and tax people as if they were individuals.... and abolish any other special government programs that discern an individual as married or unmarried.