Personally, I enjoy seeing the development, even if it's not necessarily something I'd need. The idea of a touch screen mixer has been floating around for quite some time, so I guess it was only a matter of time. And this is only a step, which maybe will pave the way for something totally different. That being said, I'm usually happy mixing w/ a mouse, one virtual fader at a time or using groups on the fly, and then envelopes.
My midi keyboard's fader automaps to the active track's volume fader, and that's about the only time when I find such things useful - in performance mode, so to speak, not having to reach for the mouse and to mess w/ the onscreen fader. That's also where I could probably use an iPad as a control surface for virtual instruments, instead of going back to the mouse.
One thing that I've grown fond of though is my laptop's trackpad and the integration of gestures in my DAW - pinching to zoom in and out and all those intuitive gestures to navigate through the project, that's addictive and its speeds things up quite a bit. Whenever I launch Pro Tools or Studio One, I miss those functions a lot - more than any actual features I guess.
I guess I'd much rather have something like that than an actual touchscreen.