Researchers at Rice University hacked a commercial Laser Cutter to create a cheap, open source SLS 3D Printer for regenerative medicine and experimenting.
If you find that you're deterred from using a 3D printer because your designs require subtractive techniques, Zmorph might have the ideal solution.
Marketing a new product is tricky. Glowforge calls itself a 3D laser printer, but it can't actually print in 3D. Makers are excited, though!