Touch screens are ok for some applications, like in Kiosks as stated.
We fit them to some of our new machines, but the commissioning Engineers or the Service Engineers (Me) fit mouses as well, we fit keyboards as standard.
Touch screens IMHO opinion for real world stuff, ie desktops, laptops are a waste of time.
Ok for large screen demos & as also stated for Idiots who buy stuff for their company who in reality have no idea about actual usage.
The real leap forward will be voice control, that actually works in real time & gets everything correct 99.99% of the time, something like "HAL" in 2001 or the gadget in Blade Runner & a few other Sci Fi films/series....I know voice recognition is out there but true voice control isn`t just yet...
Touch screens are fine on PDA/Sat Navs & the like.
In much the same way as Sat Navs are good they aren`t that good....Yet.