Evermore content is uploaded to sites like Vimeo and Youtube. I have added the fist steps to downloading this kind of content into MythTV. All you need is a copy of mythnettv from my Git. Make sure you install all the dependencies (py-videodownload, python-tvrage, py-unrar2, transmissionrpc) as described in the README file. Then subscribe to a Vimeo rss like this:

mntv subscribe "http://vimeo.com/jref/videos/rss" "James Randi Educational Foundation" "JREF"
 and start downloading the videos.