In Cuomo v. Clearing House Ass'n, the Supreme Court held, 5-4, that the Comptroller of the Currency's regulation preempting certain forms of state law enforcement against banks is invalid. Justice Scalia wrote the opinion of the Court, joined by (wait for it), Justices Stevens, Souter, Ginsburg and Breyer. Justice Thomas filed an opinion concurring in part and dissenting in part joined by the Chief Justice and Justices Kennedy and Alito. The opinion is here.
In an equally surprising development, the Court announced that it will rehear Citizens United v. Federal Election Commission, and consider whether to overturn Austin v. Michigan.
The Court also accepted six petitions for certiorari. As always, you-know-who has more details.