I tend to disagree. Touch will not work with gloves. Buttons do. Touch and rain is also a bad combination. And the most important argument is that buttons can be used without taking the eye from the viewfinder. Touch would almost be impossible here.
+1! Touch can
be handy, but in many cases, the buttons just do it better. I'd cringe if I were forced to change ISO purely by touch screen. With my 7D, I can change ISO without taking my eye from the viewfinder. I only wish more of the top LCD button functions were like that (many don't give you feedback in the VF, only in the top LCD. ISO is an exception).
Reviewing images is far easier without having to swipe the screen. Again, on the 7D, the buttons are just about perfect. You hold the camera in both hands, your right thumb can hit the review button or cycle through the histograms, or choose the delete button, while your left thumb operates the zoom buttons, the main dial, and the joystick, and you have your right index finger for the 10 image jump with the front dial.
I've owned an iPhone for 5 years, and I'm getting the 5S soon. The touch screen is great - in a phone - but I don't think I want to have to do everything on my Canon via touch. Some things, perhaps, but certainly not all.