Thinkgeek sells a 4x4x4 version for $80:
http://www.thinkgeek.com/interests/techies/d71d/
I've put it together but haven't had the time to test it out. It also requires one of these: http://www.seeedstudio.com/depot/rainbowduino-led-driver-pla...
So it is most definitely programmable, It was a bitch to solder together though.