Intrigue ABS Prematurely Engaging??

My very low mileage (~17K) 2001 Intrigue recently started exhibiting the following:

Applying light brake pressure at speeds of 50 mph and greater on a straight road, as well as at 30 mph on corners, curves, downhill ramps and driveways results in a minor, but noticeable pulsating sensation emanating from the brake pedal. The pulsating can also be mildly felt within the vehicle, although I can't really describe it - a mininal, but steady vibration that seems to come from the center front of the car.

I had a friend drive it, without giving any clues of the problem, and he concluded the same "feel." From the passenger seat, I can even hear the rumble.

We considered that a rotor is out of round. However, the rumble/vibration is uniform and not associated with a particular tire or location. Brake pads are in excellent shape, so I'm presuming there's something faulty with the ABS.

Any ideas?

Do you actually hear the ABS engage? You should hear a chattering if it actually engages not just a pulsation. I would lean more toward a slightly warped rotor or an axle shaft than the ABS based on your description. If something was wrong with the ABS itself you should have an ABS light.