The only immediate effect of revoking corporate personhood, either at the state level or by the Supreme Court, would be to cause the legal status of corporations to revert back to that of artificial entities. (We should refuse to use the old terminology of artificial persons.) They could still be represented in courts by attorneys and would be subject to the law and taxation.
However, a whole body of Supreme Court decisions would have to be re-examined. The ability of States, when granting or renewing corporate charters, to restrict harmful activities of corporations would be greatly enhanced. New legislation to protect the environment, workers, small businesses, and consumers could be enacted without worrying that it would be struck down by the Supreme Court.