D.C. Handgun Decision

So the D.C. Circuit Court has struck down the D.C. handgun ban. The rationale behind the decision seems to revolve around the interpretation of the word 'militia', which to me seems a little bit off:

The court reached this conclusion in large part by noting that founding-era militias often required the mandatory service of all, or virtually all, able-bodied, white males. Given that the militias had such broad membership, the court reasoned a broad individual right which protected all persons who participated in those militias at the time of the founding was most consistent with the historic understanding of the text.

It looks to me like they're going through some contortions to map the founding-era understanding of 'militia' to some present-day entity; I'm not convinced that such a thing currently exists. The reasoning seems to proceed along these lines:

1. We can't use the founding-era definition of militia membership, since it was limited to White males.
2. Assume instead that the Second Amendment applies, in general, to those people who form a militia, and protects their right to bear arms.
3. Project forward in time, try to find a present day analogue to founding-era militias.
4. 'Militia' was understood to exist prior to congressional enactment, and comprise a large swath of people, therefore everyone today has a right to bear arms.

The problem seems to be in step 4; I can't see how the justices went from a broad understanding of the term 'militia' to 'everyone'. I've read the relevant portion of the decision, and maybe I missed something, but based on their discussion of the meaning of 'militia' it still looks like gun ownership would have to be restricted to anyone eligible to serve in the armed forces. Specifically:

The current congressional definition of the “Militia” accords with original usage: “The militia of the United States consists of all able-bodied males at least 17 years of age and . . . under 45 years of age who are, or who have made a declaration of intention to become, citizens of the United States and of female citizens of the United States who are members of the National Guard.” 10 U.S.C. § 311

Seems to indicate that membership in the modern day militia is tied to specific eligibility criteria. How can this definition of 'militia' be used to justify gun ownership by, say, a 46 year old?

Another item, one which doesn't seem to have been taken up at all in this decision, is the predicate "being necessary to the security of a free State". What if this predicate is no longer true, would that render the Second Amendment inactive? Per Wikipedia:

When the war began, the Americans did not have a professional army or navy. Each colony provided for its own defenses through the use of local militia.

One can see how, under these conditions, the existence of militias was absolutely vital to the defense of the state. However, we've since then developed a whopping great Federal military which can beat the pants off of anything that the individual states can field. This would seem to indicate that "being necessary to the security of a free State" is no longer true with respect to militias.