in today's U.S. v. Santos: On the bottom line, 5-4 in favor of the federal criminal defendant, with the majority consisting of Scalia, Thomas, Souter, and Ginsburg in the lead opinion and Stevens in a separate concurrence, and the dissent consisting of Roberts, Kennedy, Alito, and Breyer.

This particular majority has materialized before, in the pre-Roberts/Alito sentencing factfinding/Jury Trial Clause cases; and Scalia has indeed expressed some pro-Rule of Lenity views in past cases (check out, for instance, Muscarello v. U.S., a 5-4 case in which Ginsburg joined by Rehnquist, Scalia, and Souter dissented on rule of lenity grounds). Still, this breakdown seemed noteworthy.

UPDATE: Whoops, saw that Jonathan beat me to this; please comment on his post — I've turned off comments here to make sure all will go only on one thread.