I was playing around with my Netduino tonight trying to see if I could make it, and an Adafruit Motor Shield work and power this Tayima Tracked Vehicle Chassis kit.
Success! Though as you can see nothing is really mounted, so things move around a bit. I've ordered a dual motor transmission from Jameco, to be picked up tomorrow, that should hopefully allow me to have more than just front and back movement.
The code is very simple, it just runs the motor forward for 3 seconds then backwards for 3 seconds.
The USB powers the Netduino until I wire up something else.