Solid state sensors and high torque servos are getting cheaper all the time, but it is the software methodologies that needed to change for walking to be considered a “primitive behavior”. Any kids learning about robots would, and should, assume that we have walking sorted. Getting back into standing from an unknown state, say on bumpy uneven ground — that’s still tricky. Google is going to lead the cloud based efforts on robotic vision. The points they make are simple. You can’t have enough battery power to search huge image databases to find out what the robot might be looking at right now. CPU cycles and power are cheap in the cloud, expensive on the ground in some remote location.
This little guy is now available at robot shop, but he isn’t low cost.