Arduino Robot Shield v2.1

I've felt a need for a way to very quickly and easily attach sensors and motors to an Arduino to prototype simple robots. I love ladyada's motor shield but was frustrated by it's inability to easily connect to sensors.

So far I've tested the board on my sumobots and a prototype fire-fighting robot and it works perfectly.

This is my first prototype and I'm in the process of iterating the design once more. I'm thinking I may use a NAND gate to free up an extra two digital lines and perhaps not include a built in potentiometer and speaker and instead have a mini prototyping area with .1" spaced pins. I'm open to suggestions... What do you think this board needs?

The eventual goal is to sell kits to help fund more robotics projects here at the Tufts Robotics Club (see: http://tuftsroboticsclub.com ) and hopefully help robotics enthusiasts turn their ideas into reality just a little more quickly and easily.

I have a few extra boards which I might be selling in the near future.