On the other hand, who says it won't be changed again? I have no idea what future generations will consider. For them, our laws against polyamorous families may seem barbaric. And that is the right of future generations. We all know 150 years ago men would have fought and died to prevent blacks and whites from marrying (and they did fight and die to prevent that). Today we mostly accept it. Because of the consent issue, bestiality and children will probably always remain as verboten. For the rest, I'm willing to let future Americans decide for themselves. I don't believe there is any chance we're going to change polygamy issue in the next 10 years.
No one says it, but this specific ruling never would have happened without the polling data showing a majority of Americans now accept gays. Until/unless that happens with polygamy, the court won't touch it. Well, Scalia might just to make some rant about the other justices.