The folks at Boston Dynamics are still working on semi-autonomous walking robots. You may recall my post about their BigDog robot back in 2008. The pack-robot shown here is known as the "LS3". The idea was to create a semi-autonomous legged robot to carry heavy loads -- gear for soldiers in this case. This robot is able to carry 400 lbs of a equipment, follow a human through some pretty rugged terrain, and accept voice commands. The most remarkable section comes at the end of the video when the robot takes a fall down a steep bank. It rolls over and eventually stands back up!
You can read more in this article from The Daily Mail published a few days ago.