The Supreme Court struck down the DC handgun ban by rethinking the original meaning of the Second Amendment.
Since DC falls under federal jurisdiction the ruling does not immediately apply to the states, but commentators predict an immediate deluge of court cases.
For comments and links, follow this link to the American Constitution Society and this one to the Federalist Society.
My two cents: This decision is a stretch. It has redefined the clear meaning of the Constitution, despite claims that it does not, and this redefinition has been driven by individuals who usually parse the words on the page as they are written on the page. And despite past efforts to leave policymaking to the policymakers and shun decisions that open the floodgates to court actions, this decision does both. It is difficult to reconcile this decision with past court decisions. It seems to me capricious and arbitrary.
I would have liked to see this decision wholly based on a Ninth Amendment argument that self defense is an unenumerated right that exists despite its omission in the language of the Constitution. The Ninth Amendment scares some on the court though. It reminds people that the country was founded on the belief that natural rights come first. That's a bit too originalist for this crowd.