The original Adafruit Motor Shield Kit is one of the most beloved kits, which is why Adafruit decided to make something even better. Adafruit Motor Shield Kit for Arduino v2 is upgraded to to make the best, easiest way to drive DC and Step motors. This shield will make quick work of your next robotics project! The ability to drive up to 4 DC motors or 2 step motors is kept and also many improvements are added.
Instead of a L293D Darlington driver, the Adafruit Motor Shield Kit for Arduino v2 now has the TB6612 MOSFET driver with 1.2A per channel and 3A peak current capability. It also has much lower voltage drops across the motor so you get more torque out of your batteries.
Instead of using a latch and the Arduino's PWM pins, the shield has a fully-dedicated PWM driver chip onboard. This chip handles all the motor and speed controls over I2C. Only two pins (SDA & SCL) are required to drive the multiple motors, and since it's I2C you can also connect any other I2C devices or shields to the same pins. This also makes it drop-in compatible with any Arduino, such as the Uno, Due, Leonardo and Mega R3.
Adafruit Web Site
http://www.adafruit.com/product/1438