I'm most interested in the solution of making the 3D model description. If that was possible without a lot of labor and a steep learning curve, I could live with the limitations of 3D printing for a lot of projects. Generating the data file for a complicated part is still going to take a lot of CAD time and experience, I don't see any way around that right now.
I've been hearing about 3D laser scanners that will allow you to duplicate a part, but I figure if the part is already made, I can likely buy it as a rule, so I don't know how useful that might be.