The only way to prevent that from happening is a Federal Constitutional amendment prohibiting same sex marriage and excepting it from the equal protection clause. Individual state statutes, state constitutional provisions, or even federal statutes (such as DOMA) will all fall in time, absent a Federal Constitutional amendment.
Since no one is willing to get underway with such a constitutional amendment, sit back and enjoy, cause here it comes!
Sadly, you are 100% correct on this one.