"portability is blocked by the federal defense of marriage act (assuming it stands). But I see your point, if what you are looking ahead to is the DOMA going down in the SCOTUS."
Portability is not actually blocked by DOMA. It's just not imposed by DOMA. Any state can go ahead and make the marriages of other states portable to their state if they choose to do so. It's less likely that they would do that with civil unions, given that the nature of the unions differs from state-to-state. Meanwhile, with Alito and Roberts on the bench, DOMA is less likely to go down, don't you think?
I still think there are 5 votes to take the DOMA down, if anthony kennedy is having a fit that day.