There are a few of really unique aspects to this happening on Shapeways.
Firstly the Shapeways 3D print service, with no file reading fee and a $25 minimum order that includes shipping means anyone can afford to replace a rare part without necessarily having to go to an engineer, prop maker, industrial designer or other specialist and pay large amounts of money to replace a small component needed to maintain the function or value of an item. All you need is a way to accurately measure the item then a way to 3D model it and the replacement part is only an upload away in a range of materials, one of which is bound to have suitable material properties for your particular needs. Eventually we are bound to see an extensive inventory of replacement parts on Shapeways 3D Parts, Thingiverse, Google 3D Warehouse or some other 3D model repository to make it easier for anyone to repair, replace, configure or just hack existing products.
We are seeing a person without 3D CAD skills realizing the potential of 3D printing as a bespoke manufacturing solution looking for a way to use this without tackling the learning curve necessary to accurately model the replacement part. As mentioned above we are seeing growing repositories of parts being populated over the internet, free 3D modeling tools being made available and 3D scanning starting to become closer to being a viable DIY solution thanks to the latest wave of Kinect Hacks that are bound to increase in quantity and quality. The fact remains that without one of these three the inability to 3D model your part stands in the way of you 3D printing your part unless you ask for help.
Finally we are seeing a potential revenue stream open up for people with 3D modeling skills to fulfill the needs of another individual. This could quickly become a significant business in itself as more people begin to see the potential for 3D printing we are already seeing a growing number of Shapeways community members start to make the most of their skills to become enablers of ideas.
No matter where they are in the world they can make a direct connection with the person requesting help, negotiate a price between themselves and work together to realize the 3D printed part. As well as on Shapeways, I see these requests and interactions starting to crop up in discussions on other forums, with ventures like GrabCad and on sites such as freelancer where you can bid on some of the least glamorous 3D modeling jobs possible.
Where do you see this heading, once people around you understand what is possible with 3D printing do you get requests to help 3D modeling objects? Do you think eventually EVERYTHING will be downloadable to 3D print?