In a speech to the Brady Center in October, former Justice John Paul Stevens, who dissented in Heller and retired in 2010, said the decision was wrong but limited.

“Even as generously construed in Heller,” he said, “the Second Amendment provides no obstacle to regulations prohibiting the ownership or use of the sorts of automatic weapons used in the tragic multiple killings in Virginia, Colorado and Arizona in recent years. The failure of Congress to take any action to minimize the risk of similar tragedies in the future cannot be blamed on the court’s decision in Heller.”

I'm sure that Steven's misuse of the word "automatic" in that statement wins him no favor with gun rights advocates, but his statement is otherwise essentially correct.

The conception of the Second Amendment in Heller (with reference to Miller) is the notion of a militia formed of citizens bearing arms that are "in common use" for lawful purposes. In other words, you've got a right to keep and bear arms for whatever reason you want. However, there can be restrictions on the types of arms. Although the Second Amendment isn't about duck hunting, weapons that have nothing to do with duck hunting, personal self defense, or other normal, lawful purposes aren't within scope, because the militia isn't an army - its a organization of individual citizens bearing common place arms. Arms that are "dangerous and unusual" can still be prohibited.

That conception provides a way to ban nuclear weapons, and explicitly mentioned in the Heller decision: automatic weapons. On plain consideration it would also seem that most of the weapons construed as "assault weapons" can be banned under this conception.

I think the hardest challenge to that idea which gun rights advocates can raise is the notion that "assault weapons" are needed to defend one's home and property in the event of mass insurrection or chaos. People are often quoted saying there is "no legitimate use" for these weapons. Protecting your home in the Rodney King riots would be a legitimate use.

Here is former Texas state rep Suzanna Hupp making an impassioned plea along such lines in the debate over the original "assault weapons" ban:

(Most of her testimony is about concealed carry restrictions. That is truly a policy issue, not a constitutional issue, and it really had nothing to do with the "assault weapons" ban. Its clear that narrowly defined "gun free zones" are not unconstitutional (regardless of what you think of their wisdom), anymore than restrictions on where protest rallies can be held violate the First Amendment. However, a blanket ban on carry in Chicago was recently overturned and I think that decision will be upheld - a blanket ban is probably not constitutional.)

Ultimately, I think "assault weapons" will be found to be just outside the scope of what the Second Amendment protects. Although Hupp's argument about the Rodney King Riots is challenging, at the end of the day I think that guns needed only for that sort of unusual circumstance will be outside the scope of what is meant by arms "in common use."

We can't live with a Second Amendment that allows people to own nukes. The "in common use" conception provides us with a way to draw lines without throwing the whole Amendment out of the window. Ultimately this gets us to an understanding of the Second Amendment that is rooted in the text and the history that we can also live with in our modern world.

Gun Plans Don’t Conflict With Justices’ ’08 Ruling - NYTimes.com