I see what you're getting at, and I agree that it feels quite clunky....now. But I wouldn't be so dismissive quite yet. What if in the future you could detach your screen and keep it on the table? Now, you have an actual "surface" (just like a tablet). You can play games with others on this surface . Maybe, divide the screens and then have everyone use part of their screen for their own work. (I'm just listing what I could think of doing with a really large tablet)

My point is simply that once we have touchscreens on every desktop, it might enable ways to interact with your computer that we might not even have thought of yet.

edit: added "similarity to tablet" part

Obviously you will be navigating a world designed with another paradigm in mind, the mouse, or the pointer.

This is what iOS did: Create a new world designed for being touched. Instead of the Windows CE or the Palms around the pointer.

You have to redesign the entire software stack for being touched, and it will happen.

Ubuntu Unity, Windows 8, and Mac OS new versions are races against time for being the first bringing professional creative tools "touch-ready".

It is very hard to do it, and current users are getting angry the same way people got mad when they removed the numeric keys from the macs(so command line software got redesigned around mouse).