This is a technique I learned from Jeff B (on Flickr). I don't know the precise name, but I call it 'zoom exposure'. The effect comes from zooming in the middle of a long exposure shot. This effect was not (nor could it be) produced in Photoshop:
Clicking the image takes you to its Flickr page, where you can read my commentary, download a copy of this shot, and navigate to my other WDW shots.