FCC v. Fox -- the "fleeting expletives" case

The Supreme Court recently heard oral argument in FCC v. Fox, for the second time.  The first time the Court heard the case, it denied relief on administrative law grounds: the agency's changing a rule (regarding the censorship of expletives and nudity on public broadcasts) did not require that the agency *explain* why it considered the new rule to be better than the former rule.  This time the First Amendment issue in the case seems unavoidable: what is the constitutional authority of the FCC to regulate indecency on broadcast media?  Some of my thoughts on that question are on this recent podcast.