Heller followup -- district court ruling
Here's the District Court (trial court) opinion. It applies "intermediate scrutiny" (more exacting than rational basis, less exacting than strict scrutiny) and upholds the new DC regulations.
[Of course, standards of review are judicial creations, and thus both arbitrary and malleable. When I went to law school there was no intermediate scrutiny. And in some settings the Supreme Court has indicated two different standards of review are applicable depending upon how far a law goes].