There seems to be a sudden rash of open source, low-cost 3D printer kits lately. In addition to the usual suspects (MakerBot, RepRap, Fab@Home and the very recent UP!), we now have The Ultimaker! This prototype device is being developed at FabLab Utrecht (under the name "elserbot") and seems to build on the experiences of prior projects.
While there are few specifics about this device yet, it appears to us that it may be a simpler design, meaning it may cost less, have fewer parts, easier to assemble, more reliable, etc. Of particular interest is the 2-rod X-Y axis that is much simpler than the 4-rod approach used by MakerBot. This could permit a larger build area than other designs.
There's little information present about the extruder mechanism, which is of course a critical component. Nevertheless, the goals of the project include "designing/developing an easy to build low cost 3D printer with a small form factor but large build envelope".
The result will be open source, meaning everyone will be able to build one themselves; presumably other projects might incorporate some of Ultimaker's ideas into their own designs. Let's keep watching this one develop.
The way developments have gone recently, we should have a few dozen more personal 3D printers to choose from by the end of next year!