I'm aware that in a controlled setting they have had a two legged robot walk around. But it's a controlled setting. You don't have small children running up to or passed it, you don't have people bumping into it, and you don't have lawsuits waiting to happen.
Besides, even if they had a roped off area for one of these things, the cost of building one is much more than simply paying someone $10 an hour to stand around in a fur suit.
I'm not saying I don't wish it was true. I'm saying it isn't technically, or even financially, feasible.
edit: Also, in that video notice the QR codes all over the place. On doors, walls, boxes, etc. That is how the robot recognizes the device and how to manipulate it, or move passed it. If Disney doesn't want Visa logos on the registers, I find it doubtful they want QR codes on everything.