Regulatory issues are a major concern to the 3D printing world. While the liberty to print most anything you want on demand is appealing it is not without drastic implications.
For better or worse government regulatory agencies exist for a reason.
Would you want to fly in plane with parts printed from a 3D printer from an unknown and unverified source? In the case of bio-material 3D printing would you want food printed from such a device without inspection? How about medical devices and implants? Are you ok with your surgeon acting as his/her own mechanical engineer creating designer devices?
The FDA, EPA, USDA and Underwriters Laboratories exist for a reason.
Product safety and national security are all effected by the coming 3D printing revolution.