It says nothing about the Second Amendment as conferring an individual vs. collective right. All it said, basically, is that without any evidence being presented that a sawed-off shotgun is a military weapon, the defendant could not rely on the second amendment to protect his right to possess said sawed-off shotgun.
Actually, if you take the Court's reasoning to its logical conclusion, it appears to state that rocket launchers and surface to air missles are protected, while sawed-off shotguns are not.
Thanks, interesting conclusion.