akuperma: Federal court in Utah has already overturned Utah’a ban on polgamy (a bit over a year ago) on a basis that would be applicable to all such bans.
Rav Avigdor Miller said (and reprinted in one of his recent Q&A seforim) that it is possible that one day contemporary rabbonim will end the cherem. The Vilna Gaon also said he was in favor of ending it.