Superfly, I think your opening summary sums up FBW very well. I think that FBW is nowadays generally taken to mean control through computers, (others correct me if I'm wrong).
In Airbus FBW, amongst the other non-pilot commanded 'changes' the computers may send to the control surfaces are; Approx half rudder towards a live engine in the event of engine failure; Attitude "stability" involving accelerometers giving feedback to the flight control computers to keep the aircraft in roughly the same attitude the pilot last commanded - (not a perfect system, only the autopilot will keep the aircraft in exactly the right attitude for the particular navigation required); and Turbulence load alleviation/damping, (can't remember the exact name), where spoilers and ailerons are used to reduce wing flex in strong turbulence.
Other 'xxx by wire' systems on Airbus include the nosewheel steering, and of course the engine FADECS.
(The only mechanically operated control surfaces on most Airbus are the rudder and the horizontal stabiliser, but both of these still require hydraulics to work).
Good luck!
Last edited by Uplinker; 24th Mar 2013 at 13:17.