I rename my photos in Lightroom 3 at the time of import with Camera Make + Filename. This works great to distinguish the photos between my Nikon D3s and Nikon D3x. Unfortunately, video taken with the D3s does not have the Camera Make field in the .AVI file and when you import the pictures, Lightroom "hangs up" looking for the Camera Make. A popup window that allowed you to create your own name or a way to fill in the information manually would be helpful. At least, it should import the avi file and notify you that it could not rename the file properly.
Thanks