I tried this today at SIGGRAPH E-tech. Very strange feeling but actually almost believeable if you close your eyes and take little steps. These are little robots that flock around and postion themselves in the right place under your descending foot. Amazing.
And as an aside, this was developed by Professor Hiroo Iwata's lab at Univ. of Tsukuba - he's had something in the emerging technology show every year for he past 11 years...

It was indeed amazing to watch the platforms auto adjust and move around. Not sure what was happening behind the scenes, but it felt like it wasn't tracking your movement, but rather moving at a constant cycle. The question I have is, would it be better to have lots of little platforms, or a fewer large platforms? Adjusting to simulate friction seems like it would be a nightmare...

Couldn't help but be reminded of the scene in X-Men where Magneto breaks out of plastic prison and walks across space while controlling metal platforms.