Almost exactly as I had said.
We do not think it profitable to parse these passages of Heller as if they contained an answer to the question whether [a particular statute] is valid. They are precautionary language. Instead of resolving questions such as the one we must confront, the Justices have told us that the matters have been left open. The language we have quoted warns readers not to treat Heller as containing broader holdings than the Court set out to establish: that the Second Amendment creates individual rights, one of which is keeping operable handguns at home for self-defense. What other entitlements the Second Amendment creates, and what regulations legislatures may establish, were left open. [Heller] is not a comprehensive code; it is just an explanation for the Court's disposition. Judicial opinions must not be confused with statutes, and general expressions must be read in light of the subject under consideration. — United States v. Skoien (.pdf; 38 pgs.).
h/t Michael O'Hear.