I really don't think it will take away from the art of model building. A person still is going to have to develop the skills of scratch building and putting the kit together. A person doesn’t just go to a store to buy horse shoes, you go to a Blacksmith that has the skills to make the correct. My point is that if you still want something custom made you will have to go to the person with the skills to do it. Anyone can slap a model together but, it takes a person with the skills to give it life. That’s why I don't think 3-D printing will change the art of modeling that much. It will only be another use to use the skills developed by the scale modeler. Another medium in which to create an appealing static model to look at.