If the front camber is negative (the wheels are slanted inwards at the top), and you are on stock suspension, I would look into the possibility of sagging springs. Replacing your shocks & springs may help with the issue at hand.

If your brake rotors are warped, you will experience vibrations in steering at higher speeds.

You might also have worn bushings or ball joints. If you are not performing the work yourself, I would suggest getting to a shop immediatly before things get worse.