Add a screencasts page to the site similar to railscasts.com
Screencasts can be hosted on any third party service but vimeo seems to provide the best quality. Then aggregate these screencasts to one central place. Railscasts.com is a good example we can follow.
Vimeo exposes feeds with certain tags. All we need to do than, is to comeup with an official tag, like castlecast, and build an aggregator page, similar to blogs page. Perhaps we'd need some kind of moderation also, to ensure no accidental videos, show up.
And of course, most importantly we need the gist of this idea - the videos themselves :)