This little number is an interface board for any BS2-compatible or Stamp Stack II controller, it is intended for use with products that were designed to accept Solarbotics add-on brainboards such as the Sumovore and ScoutWalker III.
The Solarbotics Sumovore Kit is a strong, modular design with over 500 man-hours of development and 21 prototypes behind it. It has more power, speed, and is less expensive than the Junun Mark III, Parallax Mini-Sumo, and Tab SumoBot.
Pololu is known for some killer motor driver technology. They're bringing their mojo to the Arduino! Dual robust VNH5019 motor drivers take 5.5 to 24 V and punch out a continuous 12 A (30 A peak) per motor, or a continuous 24 A (60 A peak) to a single motor connected to both channels.