The whole concept of 3D printing is well established and the overall hype has died down to some extent nowadays. The goal then is to now find practical solutions that solves real world problems.
One area to explore especially in developing countries is the concept of reducing waste notably plastic while creating real manufacturing solutions. 3D printing is a good candidate but does have special requirements in terms of material composition. Thankfully, there are solutions emerging such as the ProtoCycler Product. Popular Science did a great article on how this product came about - Feed Your 3D Printer Recycled Plastic.
While this is great and a step in the right direction, the next phase is to push more open source solutions to reduce the overall cost significantly.