The U.S. Supreme Court hears argument today in Skilling v. United States. Former Enron executive Jeff Skilling challenges his conviction under 18 USC 1346, which criminalizes “a scheme or artifice to deprive another of the intangible right of honest services.” In addition to arguing that his trial was prejudiced by publicity in the Houston area, Skilling argues that Section 1346 is unconstitutionally vague. This argument could have consequences on public corruption prosecutions like that of former Illinois Governor Rod Blagojevich.
As SCOTUSblog notes here and here, this is one of three honest services fraud cases this term. According to Lyle Denniston, the other two cases (which were argued in December) don’t raise a direct constitutional challenge to the law, but there is some reason to believe that the Court is “quite interested in the constitutional question”:

Three days after the Skilling merits brief was filed, with its direct complaint about the law’s validity, the Court moved the Skilling case ahead on its docket, to give the Court an earlier chance to hear lawyers’ argument on it. No one outside the Court knows why it advanced the case, but the Justices clearly were keen on getting to it.