It is amazing how fast 3D Printing is advancing. Current technologies are peaking at 10x10x100ùm with 1,000,000 colors. This is remarkable indeed.
As we get closer to 1×1ùm printing and full color the only real consideration will become the price of colored plastics. Plastics are so cheap that one could concievably print out 10 terabytes for $2 (and cost of the Printer, but the Printer would let you print as much as you need to).
This memory type of course would require a whole new reading system but his will not dramatically increase the costs when one is printing thousands of terabytes of data. Light is the fastest of readable memories and plastics have very long shelf lives.