Already possible
Funily enough today I wrote a small application to view a 2000x2000 res photo (that was too big for the screen). I needed to be able to move it left right up down.
I loaded it into an Imagebox and added some code so the rate at which it moved was proportional to the 'swipe of my finger' (using the MouseMove function)
Image.left=Image.left+rate ....
Then I made it slow down after a while like the Iphone does when u scroll through things
rate=rate*0.95 did that.
And come to an immediate stop if I just tapped the screen again (using MouseDown) rate=0
Anyway Ive got TouchFlow functionality on my PhotoViewer - so already possible with Basic4ppc- its just coding.
The only thing u CANT do, is two finger stretching of an image. I think that WM, or even the touchscreen hardware may limit the number of simultanious screen presses to 1.