They've taken the RepRap design and made it a whole lot simpler. They've made it smaller, more portable and changed some of the design. One of their optimizations is to reverse the motion paradigm: Instead of moving the heavy extrusion head during printing, they move the very light tray. Another innovation is to use wooden panels instead of the more fragile acrylic equivalents.
Their design is open source, so you can actually build your own makerbot, but they recommend buying the kit from them as it can be tricky to source all the parts efficiently. Being open source means you can tinker with the design. Really, they've made a platform from which we have no idea what might emerge. Adam's favorite unexpected item is a bathtub plug, which has given the world "cleaner nerds".
Adam also describes Thingiverse, a web site facilitating the sharing of 3D designs. We believe repositories of models is an essential part of an effective 3D environment, and Thingiverse could become much more important in future years.
There's a fascinating walk-thru of the entire sequence of printing, from design to motion of the build platform. A live demonstration of an ABS print takes place, showing some of the techniques they've used to overcome the stickiness of ABS. Ok, so we're nerds here too.