I am really tending to think that this problem is caused by the brake pads/rotors. Before I took it in to have the brakes done, the car was fine -- it had no vibration whatsoever. It started up right after I had the new pads and rotors. I'm tending to think that it is not suspension-related as the mechanic thoroughly checked my suspension and found no problems other than the wheel bearing & idler arm which were replaced. The tires are worn -- I'll need a new set of them pretty soon. But before the brake job, there was no vibration at all. The tires are wearing fine. I checked them and they all look fine.

I'm guessing that because I'm still getting vibration in the brake pedal with new pads/rotors that something is probably off kelter. I'm going to take it in on Monday and see what they have to say about it, and will post the results.