Well done! You might want to work a bit more on the mechanical side but as long as it does the job... I like your documentation on the website as well. So what's next? Your homepage says xbee (RF?) and bluetooth communication, why both? What are your plans with it? It'll be nice to control it through a web interface and get feedback from that wireless camera you have installed!
ps: your molecubes project reminds me of this post I read today http://blog.makezine.com/archive/2008/04/shapeshifting_robots.html
The mechanical need to be improved for sure, but it is much better than at the beginning... The difficult part was to fixe the wheels with the hubs on the servos.
For the communication, I want try xbee and bluetooth to learn how to use them (but this will depend of my budget). For sure, It could be nice to control the robot from the web with the camera but september the project will still like this.
Do you have any experience with bluetooth or xbee? Which one do you prefer?