I have a little different opinion on this one.
During rudder yaw, the effect on pitch and roll is not due to air over one wing being faster than the other. If this was true then the effect would go away after establishing knife edge flight.
The profile of the fuselage plays a big part in this. The airflow traversion the fuselage usually causes a plane with a high aft canopy deck will pitch more to the belly than one with a low aft deck because the fuselage top and bottom are developing different levels of lift. This will cause a pitch and a roll moment that is more significant that the airflow differential over the wings.
ORIGINAL: JapanFlyer
There is no secondary effect of ailerons as there is with rudder. Ailerons turn the aircraft. Rudder yaws the aircraft, but in so doing, one wing travels faster than the other, generates more lift, and the aircraft turns as a result, but generally not as effectively as with ailerons. The rudder is also effective down to very low speeds, and that's why it's used in stall turns.