Bit of an update:
3D Systems, spurred on by the increasing competition in the 3D printing space, has introduced their Continuous, High-Speed Fab-Grade Printer, which is intended to increase fabrication speeds by up to 50 times from the current top-of-the-line 3D printing technologies. 3D Systems' VP of Global Engineering, Jeff Blank, reports that the printer can accurately place 4 billion drops of color photosensitive material each minute. The system's multiple build platforms operate on a race track-like structure which take the platforms around the track and off ramps to different areas upon printing. See more details about this potential future for mass additive manufacturing in the full article: http://3dprint.com/29472/3d-systems-high-speed-printer/

Below is a photo of the system: