"Touch" input is ideal for smartphones and tablets.
On a 27" screen, "touch" however, is not the answer.
Imagine for a moment sitting in front of a 27" screen and having your arm raised for hours on end just to do any work. You would have employees screaming Bloody Murder in no time at all.
Microsoft has been made aware of this numerous times since they proposed it.
Having a separate desktop UI would not be that difficult to create and would go a long way to make Windows 8 desirable for desktops.
Did they listen? It doesn't look like it; does it.