Ashcroft has done a great service by moving the government position so far in favor of individual rights. When the Supreme Court grapples with defining the limits, they will be faced with the same type of problems that caused Roe v. Wade. If the government must draw a line in a situation of almost infinite gradations, then the line should be drawn at the limit which preserves freedom, however unpopular and disgusting some may view the exercise of that freedom.
But there is at least one stark difference. With the right to bear arms, the SCOTUS has text in the Constitution, part of the Bill of Rights, that is --DIRECTLY-- on the point. In addition to this text, there is "legislative" history that explains what the drafters of this phrase had in mind. The SCOTUS did not have this sort of guidance when they passed down Roe v. Wade.