He states that the court held that the Second Amendment protects an individual right for lawful purposes including self defense.
2) Some restrictions of the RKBA are ok, licensing is not forbidden, but it must not be arbitrary or capricious
3) Outright bans of arms in common use are forbidden. Handguns are in common use, but machine guns could possible be banned. Perhaps the reason machine guns are not in common use is because of their heavy regulation for the last 70 years.
4) The Supreme Court declined to specify a standard for review of a Second Amendment base challenge to gun laws.