The most recent important cases on the Second Amendment have greatly broadened the meaning of that amendment compared to the jurisprudence that had existed before those cases. These cases were District of Columbia v. Heller in 2008 and McDonald v. Chicago decided in June of 2010. In these cases, the Supreme Court found for the first time that the Second Amendment creates an individual right to own firearms (as opposed to a right that is connected only to military service). The first of the cases applied only to federal law, the second applied to state and local governments.
Now that the Second Amendment has been interpreted in this way, further litigation will be needed to determine what kinds of gun control laws, if any, are acceptable under the new interpretation.