This could get very interesting if you decided to put some redstone circuits into the model. Yes, I realize that redstone doesn't exist "in real life", but the logic behind redstone certainly could be adapted into a 3D printer like this and give you the ability to make real-world electronic circuits on the fly and have them buried into some kind of device that you make using this method.
Just a random thought. It is an amazing concept. It sort of blurs the line here between the virtual and "real" worlds and makes me wonder if Minecraft really is "The Matrix 1.0"