I can understand your reasons for believing that, but you are wrong. The Court did not strike this law on federalism or states' rights grounds. It was struck because the Court held that the motivation behind the law was unjustifiable animus towards gays. Dicta or not, thatis some pretty powerful language. The next step for the gay rights activists will be to sue all the states that have protected traditional marriage. They will now be able to cite to Supreme Court precedent that at least strongly suggests that banning gay marriage serves no rational basis and doesn't survive scrutiny. This case was not nearly as sweeping as Roe, but the end result will still be a lot of invalidations of gay marriage bans by the states.