Quote Originally Posted by thekingb View Post
Even at 1/2000s shutter, could there be blur caused by the fast panning of the camera?
Yes. Here's a few examples of past panning shots of Zuni running for a ball. Press L to go into the lightbox, or choose to view the Large size.

Zuni @ 1/2000s http://www.flickr.com/photos/15493374@N03/6457476577/in/photostream/

Much easier to see the blur on Zuni @ 1/1600s http://www.flickr.com/photos/15493374@N03/6457475287/in/photostream/

If I can get foreground blur, you can definately get background blur, as it will pan by faster.