In a great interview with CBS, Cody Wilson of Defense Distributed declares that the "debate is over" in terms of the availability of 3D printed guns.
Honest, well intentioned people can have genuine concerns about what this means for society, in much the same way that concerns exist about the existence of pornography or certain types of drugs. Those concerns, however, don't change the fact remains that designs for 3D printing guns are obtainable and there is nothing the government can do to change that reality.
In a better world, this would serve a reminder to society of the limitations of politics and government. Government, after all, is simply force. The only thing the state can do is attempt scare the population into giving them further powers to hunt down individuals who choose to access these files - which is precisely what we are seeing now with the political theatre playing out in Washington. It can even go further and harass Mr. Wilson, perhaps even try to throw him behind bars next to Ross Ulbricht. Perhaps it can go even further and use the threat of "ghost guns" to give the state new powers to regulate the internet and try to control data.
It can't however, change the fact that Cody Wilson's designs exist. For all the power horrific government has, it simply can't change that.