Though this does not spell doom for nation-wide gay marriage.  While there is a more traditionalist social backlash occurring at this time, international pressure from Europe and Latin America along with domestic gay activists and portions of the press have begun to squeeze the Supreme Court of the United States.  With the pressure growing, it seems as though the Court will be forced to review the definition of marriage soon.  A positive decision on the legality of gay marriage could result in the spread of equality in other nations, such as the United Kingdom.  
I believe that the American government, no matter which branch or level is prompted into action first, will eventually do what is right and nationally legalize same-sex marriage.  Though we remain an unequal society now, eventually there will be freedom nationwide for gays to marry and hold the same rights as heterosexual spouses.