I was thinking about the exact same thing too! Just yesterday.
I was fantasising abou it, about running windows on a tablet.
The only plausible timeframe is in 2012. When Windows 8 is released, it will be the first Microsoft Windows OS that will be fully touch, and Qualcomm chipset compatible.
I'm planning on running a dual boot WebOS/Windows 8 HP Touchpad.
Oh, can't we all just dream?!!!
One finger is left click, two fingers will be both left, and right click. And three fingers will account for a lone right click.
Wouldn't that work? And shaking the pad will enable a virtual keyboard, or some such.