Yeah, a footstool is all this could really be. On a related note, I'm really, really wondering what the geography of this stage is like; we've seen so many pictures of it, and so far all I can say for sure is that it has a platform and some kind of ground that is not near said platform. That's not really anything to go on!
Also, Sakurai's comment and the general timing of things makes me believe that we're about to get something new soon that's bigger than what we've seen recently, perhaps another gameplay video. The game is obviously far enough along that those are feasible to make, and it sure does build a lot of hype. I don't think they're just going to leave us hanging for info for super long periods of time at this point largely since they've already opened the floodgates and have all of our captive attention; they're going to want to keep it clear through to release whether that's easy to do or not.