I've been following the Claytronics and Modular robotics for a while now..
However until recently all systems where either to big or too simple:
A revolution was required and today I learned about what might just be it: Harvard's Monolithic Bee.
"...a millimeter-scale flapping wing robotic insect produced using Printed Circuit MEMS (PC-MEMS) techniques."
I cannot avoid raising hopes on how this technology can speedup developments on Claytronics/ Modular Robotics on the micro-scales.