[mgatepi]

I would think utilizing a GOM or FARO style laser scanner somehow communicating with a CNC machining center is what you are talking about. Laser scanners are extremely accurate, we actually have 2 here and they scan to the micron level. The key would be taking the point cloud that these produce and somehow making a machining center understand this by converting to some sort of surface recognized by the CNC machine.
Is this possible....maybe....but you are looking at a huge investment.
We scan part surfaces all the time here and for tooling repair work, we can download this file into a CAD software and create the surfaces we need to duplicate the shape. So really this technology exists. How to actually use the scanner to teach the CNC machine....thats next level.