"...evidence that some dramatic features of the earth's surface could be the result of relatively rapid shifts in the direction in which crustal plates move. Rather than simply drifting along in straight lines over millions of years, plates can be pushed aside or even be made to reverse direction due to convection in the mantle far beneath them."

Ever wondered why there are volcanoes in Hawaii, in the middle of the plate, whereas all the others are along the Pacific rim?

They are above a big hot spot in the mantle. By following the trail of extinct volcanoes in the area, scientists (or even you and I) can see the movement of the crust, and how long it took to move.

As usual for this type of story, they don't say how much more rapidly, just more than thought.