I use touch screens at work. Based on my experience, touch screens are rarely preferable to the keyboard and mouse. It is usually slower as well. After reaching up repeatedly, it is uncomfortable on your shoulders. As mentioned above, there it always the sweaty/wet finger problem. Just took a sip from your ice cold water bottle? yep, gotta dry off the hand before the touch screen will work.
Hand held phones work well with touch screens because you can place them at a comfortable height and adjust on the fly, with a monitor that is going to be an issue. Monitor placement will be a huge consideration.
The place where I think touch screen DAW's would be handy is, when you are tracking alone from the "live" room and cannot reach the console, you can set up a remote touch screen to control the record, stop, undo etc functions. As far as mixing, editing or doing any in depth and lengthy work in a DAW, I would not want touch.