Hmm, there was a thread here a little while ago with some kind of robot scissor thing closing that had motion blur. The animation initially posted wasn't great, and it spawned a lot of great advice as I remember about motion blurring. I can't find the thread as I don't remember who posted it, but maybe someone else here will be able to post it. I think it might be of some help in this direction.
The thread, titled Lectro Mockup Madness, was posted by Souly.
Here is where the motion blur discussion begins:
http://www.wayofthepixel.net/pixelation/index.php?topic=4925.msg62315#msg62315
