During the recent Back to the Mac press event, Steve had this to say: "...Touch surfaces don't want to be vertical. It gives great demo but after a short period of time, you start to fatigue and after an extended period of time, your arm wants to fall off. It doesn't work; it's ergonomically terrible."
Bosley responded in an interview with DVICE. He admits that a touch interface probably wouldn't be optimal if it were the only input mechanism for a vertical screen. However, he emphasizes that each of the TouchSmart machines offers users multiple inputs, including keyboard, mouse, and touch. Users are free to use whichever they like.
Bosley also notes that the orientation of the screens on its machines can be adjusted for use with touch. For example, its touch-enabled laptops are convertibles with screens that flip around and lay flat, essentially turning it into a tablet. Similarly, the desktop screens can be made more horizontal. Despite this, HP's TouchSmarts are generally not considered to be huge sellers, especially the laptops.
Bosley's arguments do lend credence to the idea of a touch-enabled iMac with an adjustable screen (like the one seen in a recent Apple patent). Such an arrangement would provide the horizontal surface that lends itself to touch. Would you want such a convertible desktop machine? Have your say in the comments.