Still haven't got it have you? The speed of the plane isn't determained by the wheels and it isn't determained by how fast the propeller is spinning. It is determained by how far it goes in a certain time. Very simple concept. In your senerio, assuming that the plane has good bearings(ie...low resistance)...then the propellors would barely have to work to maintain a stationary position. Just enough to overcome the rolling resistance. As soon as you rev up the engine to take off capacity, the plane will move forward and take off just as it normally would regardless of how fast the treadmill goes because the wheels have a definate amount of friction and it doesn't matter how fast they are going.
