> I'm not sure why press, media, futurists insist on pushing the idea that the future of user interaction is via replicating 3-dimensional physical interaction. There's a reason the keyboard, mouse and (small) touch screen are so successful as input devices. They each create an huge degree of meaning with a high level of precision, for relatively tiny physical movements.
While the advantages you mention of a keyboard/mouse/touchscreen are correct, I would not say that is the reason they are so successful. The reason they are so successful is because up until recently there was no competition to either of these. They are the default winners in the world of today, because they were the only ones racing yesterday.
When Doug Engelbart presented the Mother of All Demos back in 1968, he introduced both the mouse and the chorded keyboard, yet the chorded keyboard never caught on. And in 1968, the mouse was a new competitor to the light pen, which had been introduced in 1952. And just in case you don't think the light pen got a fair shake, remember that the IBM PC came with light pen support on both the CGA and EGA cards, and with support in the BIOS and in BASIC. There was no support for the mouse.
While the advantages you mention of a keyboard/mouse/touchscreen are correct, I would not say that is the reason they are so successful. The reason they are so successful is because up until recently there was no competition to either of these. They are the default winners in the world of today, because they were the only ones racing yesterday.