I've submitted the Comments thread and License extensions as Internet
Drafts. They should post in the coming few days. In the meantime, the
latest versions can be found at the locations below.
http://www.snellspace.com/public/draft-snell-atompub-feed-license-00.txt
http://www.snellspace.com/public/draft-snell-atompub-feed-thread-00.txt
As a reminder, the license extension provides a link relation for
associating a copyright license with a feed or entry. The most common
use case will be to associate creative commons licenses with feeds.
- James