Poynter Online has published an article about the Ken Burns Effect (pan and zoom), which includes information on how to best use the effect from editors such as… Ken Burns.
For Burns, any motion on an image comes in pursuit of meaning. He says there are no hard and fast rules: “All there is is what works; that is to say, what ultimately has meaning. I’ve been guided for more than 30 years by a sense of the primacy of the individual image to convey complex information. As I became a filmmaker, I trusted that still photograph to be a representation of a moment that was once very much alive. And so I treated it in much the same way that a filmmaker would a long shot, therefore having the possibilities of a medium [shot], a close [up], a pan [across], a tilt [up or down], a reveal, all the devices of cinematography within the seemingly static still image. And I not only looked at the photograph, I listened to it — all in the service of meaning, what it is I’m trying to communicate, what I’m trying to do … What we seek is meaning, and any movement, however dazzling or frenetic, if it doesn’t have meaning, it doesn’t have a place.”
(Link via Camcorderinfo.com.)
Jeff Carlson | Never Enough Coffee Creations 
At first he really did make a huge impact. the Civil War had a huge influence on me, but later on he kind of became a one trick pony. IMO anyway.