My 2000 ssei has a steering wheel vibration and pulsing when I apply the brakes over 55. I've looked at the pads and rotors and they appear fine. The prior owner mentioned something about a wheel bearing and or bad races in a bearing, which was apparently what a local Pontiac service adviser told him. Anyone heard of a bad bearing or race issue that needs to be looked at? I don't want to pull things apart to look and I don't have anything to compare it with when I take parts off.
I had a similar problem to what you are describing, and mine was a bad rotor. I used a micrometer to check the thickness of the rotor at multiple places around the rotor and determined that it was thicker in some places, even though you cant see it with your eye alone.