Marius Kintel, the creator of OpenSCAD, discusses the merits of Multi-color multi-material 3D Printing on the ORD Solutions 5 extruder system.
http://ordsolutions.com/
They had very successful Kickstarter:
http://www.kickstarter.com/projects/ordsolutions/5-color-material-3d-filament-printer-made-in-canad
Update:
Here is a detailed guide on how to set up the MH3000 from beginning:
http://diy3dprinting.blogspot.com/2014/09/how-to-setup-ord-solutions-mh3000.html