This "auto sensing" method of switching between Active Digitizer and Touch (multi or single) is not my preferred method for switching between the two input methods. I much prefer the way TabletKiosk does it on the Sahara i440D with a physical switch for alternating between the two input methods. This allows for a truer Touch experience when in Touch, and truer Digitizer experience when in Digitizer, without all the idiosyncrasies.
Right-click Multi-Touch Win7 Pinch Gesture
Here is a photo of pinch gesture in action (I like that it allows for a zoom-styled response in dialog boxes) and a photo a right-clicking (by a single finger on the screen and concurrently tapping with a second finger to create a right-click dialog box).
No Pinch Gesture in use
Zoom-in Multi-Touch Win7 Pinch Gesture
Zoom-out Multi-Touch Win7 Pinch Gesture