I'm also interested in learning more about the throttle pedal being electronically connected to the engine vice the old-fashioned way?
Old way: throttle cable directly connected to throttle body.
New way: Gas pedal has a potentiometer(variable resistor) and a heavy spring.
Throttle body has a stepper motor attached directly to drive the throttle plate.
Electronic controls and wires in-between the two, hence drive-by-wire. The benefit is possibly quicker throttle response and other things that mileage misers(EPA) want. The idle speed control is super easy this way with the throttle controlled by the ECU.