Can someone explain to me why it's important to duplicate the our mediocre human design for the robot? Our design is fairly flawed, mechanically. I understand the "let's not scare people" idea, but is that concern actually relevant?
IMHO, by the time any of the robotics technology is ready to go into production, that the old people they were worried about scaring will have died long ago, and those old people will be replaced by people who are today in their 40s or so.
I think it's fairly safe to say that today's average 40 year-old understands the concept of robots and wouldn't be particularly frightened or even concerned by the presence by a robot having four legs and two arms, even if it was standing upright. The designers could benefit by simplified balancing and all the practical working knowledge available on multi-legged movement.
I'd probably be startled to find a Big Dog checking me out at night in a hospital bed, but some upright robot with the suitable production coverings? That'd be okay.