Like most data-driven technologies (such as GPS and cellular data), the future of OBD-II technology lies in convergence.
For example, newer OBD-II scanners and readers are starting to integrate Wi-Fi technology to wirelessly connect to a nearby laptop or smartphone for easier monitoring of a vehicle in a garage or on the road. For example, the OBDKey WLAN and the PLX WiFi allow a nearby iPod Touch or iPhone to stream OBD data for use in an app such as Rev or DashCommand.
GPS device manufacturers are starting to get in on the OBD-II game as well. Earlier this year, we saw the announcement of the Garmin EcoRoutes HD system, which pulls OBD data from a Bluetooth dongle to more accurately measure your fuel economy and driving habits to tell how greenly you're driving and how you can improve.
As aftermarket accessory manufacturers gain more experience with the OBD-II standard, we may begin to see even more innovative uses for this data. Maybe some enterprising GPS manufacturer will figure out how to use the OBD supplied vehicle speed and steering-angle information to increase tracking accuracy in urban canyons and tunnels. Whatever the next cool application of OBD tech will be, we think there's still plenty of mileage to be gotten out of this little port.