In general they rotate in the same direction.
I can think of two situations where the rotation is opposite.
First is a technique known a plugging, where you use a reversing switch to change the direction of field rotation in order to stop a spinning motor. In this case the rotor is _trying_ to spin in the same direction as the rotating field, but because of inertia is spinning in the opposite direction and slowing down.
The second is if some defect or event in the motor enhances negative sequence harmonics so much that the motor rotates in response to the harmonic field. In this case the rotor is following _a_ rotating field, just not the main desired one.
Jon
