I wrote up a quick library that will get steppers running on your Arduino Due with the fantastic Adafruit motor shield. Right now I've only got interleave stepping incorporated; in the future I plan on adding options for acceleration and possibly other features for those that want. The library isn't as pretty as the Adafruit one (agh I don't know how to do bitwise manipulations!
Just download the zip (below), open the Arduino IDE, click on Sketch --> Import Library... and select the downloaded zip! I even included a little example for you all to play with
Enjoy and let me know what you think!

