This robot from Tsinghua University walks like a human. It looks like it is about the size of the Darwin OP. Its frame design is not too different from Poppy so maybe the team can study the method and make Poppy walk?
Video of the robot stepper 3d walking:
I think I found the academic paper describing the robots construciton but I am not qualified to analyze it. I posted here hoping someone more qualified would study it. I think if you are from INRIA you can download the whole article.
btw they have an older version of this robot was walking already in 2008.
Video of stepper senior:
Another video of stepper senior: