Idea: The Absolute Killer Feature of Windows RT

Hey guys,

I just thought of the most insane feature for the Microsoft Surface and I want to share with you my idea.

Microsoft, you'll thank me later.

One of the virtues of Windows 8 is also one of its biggest problems: it's designed with touchscreens in mind, so navigating the Metro UI with your mouse at your desktop can become a bother.

So what if you could use your Windows RT device as an input device for your Windows 8 desktop?
The contents of your main monitor would be mirrored to the RT device and you would control what happens on the big screen by touching the small one.

What do you think? The single most mental feature ever, too complicated or technologically improbable?