I might not have explained it clearly enough.

The problem does go away at higher speeds, but then it STAYS gone even when i slow down.

Pretty sure its a stuck caliper pin. Will have to wait until my day off to take them apart and lube em up.

alignment or wheel balance/warper rotors wouldn't explain the sudden change in range of motion of the brake pedal. Instead of having a good 2-3 inches of play before the brakes engage(normal, no vibration when its like this), its more like 1/4" before the brakes are fully engaged (and bad vibration occurs anywhere from 40-60+mph).