Wow! Someone else on this thread that can actually think outside of their small insignificant little individual world.
There are many uses for touchscreen computers. They just may not be ideal for surfing the web, updating Facebook, syncing an iPod and posting comments on MR.
Long before there was even OSX a subset of Macphiles were seeking and requesting OS support for touch screens. It was not forthcoming. There were some third party applications and vertical market applications that employed both MacOS (8 and 9) and a touch screen, mainly for kiosks.
By simply having OS level support and a manufacturer and ecosystem supported GUI, IO and system, many of those applications will emerge again. Many years later.
I think we could see different form factor uses of the device such as a canted desktop, a coffeee table, a bartop surface, slot machine like (iMac like) workstations.
The current implementation is handtop computing, but as the visual surface gets larger, it will be a fixed position use. By having remote gesture capture devices, such as an iPhone as a gesture remote for a 52" screen, there is less of a need for touch sensitivity on larger screens. So it will be interesting to see why now.
The "new" screen is not only a display, but a gesture capture device from touch and motion, as well as a visual capture device. The screen itself simply does more things now (well, soon anyway).
Rocketman