Marriage isnt a state issue today, there is no way that states will be allowed to ignore families that relocate or get transferred there by the federal govt, and military, pretending that gay marriage is a state issue is a way to get r done for gay marriage nationally.
Besides the feds have to decide on many millions of marriages itself, such as in widow benefits and immigration policy and in the military and federal employment.
Gay marriage has already been recognized by the federal government, the military, and in immigration and several states, no state is going to be able to stop those families at their borders or with a separate set of family laws.
You talk like it is a done deal. If so, why fight it?
They will continue to get Fed benefits but an non-gay state is under no compulsion to give state benefits.
Besides...the number of gay married people who work for the fed gov't and will be relocated is SO low.
Only 2% of the population is gay...even less are married or will get married (they are notoriously promiscuious) and even less have a federal job that will require relo.