My company has a DesignJet plotter (which is basically a way oversized inkjet that produces 3-foot by 4-foot plots), but this printer is the next generation.
Basically, it uses cartridges filled with plastic, instead of toner, to "print" a real object, instead of a picture of it. So, basically, you upload a 3D model or design to the printer and then it lays out layer after layer of melted plastic until the object is created. The typical example is an adjustable wrench, but people have created working flutes, and much more complicated stuff. There is even a web site (Shapeways) where you can upload a design, using the site's software, and they will produce the prototype for you on their printer (which also uses metal in addition to plastic).
In the future, you will be able to replace broken plastic toys, glasses, and other objects in your house, by getting the design from the manufacturer online, and then printing the replacement yourself. And you could also create a lot of really cool/ugly jewelry dinnerware, artwork, etc.