The lawsuits from polygamists may well pass, I guess, but then again it may not, depending on how important the number "two" is to marriage. Those threatening to marry their animals don't have a cat's chance in hell of winning any lawsuits. After all, the second party to the marriage, the animal, is not a "person" under any legal definition, and cannot offer consent to the marriage. So a slippery slope to bestiality isn't going to happen, not now and not ever.
It is a bit of a legal mess, though, and I am, in fact, one of those that was surprised by the Supreme Court's decision. Marriage between same-sex couples ought to be legal, in my opinion, but the ruling that found that it was a constitutional right seemed to me to be a bit of a contradiction -- the entire problem being that even 20 years ago, let alone 240, same-sex marriage was barely envisaged, if at all. Still, the SC apparently felt that it was constitutional, this time at least, and state officials at least have to abide by that decision. The protests are going to roll on and on, I fear.