They take their time to "print" stuff. Unless your game takes hours to load a scene, I don't see them printing directly usable things for a game.
I first saw this technology like 20 years ago and its become easier to do and faster and will probably become alot faster yet (and cheaper).
Timeframe may be something like in next 5 - 10 years
Most likely you would not own the machine yourself but would go to a machine at your local supermarket like the way they have photo printer machine now.