I've started experimenting with doing video screencasts in the interface section. You can see an example of the first one here: Gawker Media Video Comments. Scroll to the bottom of the screenshots for video--which we're going to use Vimeo's excellent video publishing service for the hosting. Here's a preview of the first video:
I think it makes a lot of sense to do this for interfaces because screenshots simply cannot reproduce the experience of transitions, motion, and AJAX interactions. Let me know what you think.