I have a 2006 Toyota Sienna LE with 35000 miles. Frequently, immediately upon touching the brake pedal, I feel a vibration in the pedal, just for a fraction of a second. The vibration occurs before braking really starts. This happens on dry pavement, and might happen more frequently after the cruise control has been used. My dealer has replaced the brake light switch, thinking that if it was intermittent, it might cause the ABS to do something wierd, but they could not observe the problem.