We're constantly working to enrich the sidebars across Kinja. Today, we rolled out an enhanced version of the sidebar on permalinks.
When you land on a Kinja permalink, you'll see a sidebar powered by the recent activity of that page's owner.
On a permalink, it's the recent activity of the post's author. On a reply permalink, it will be recent activity of the author of the reply.
For now, we're using recent recommendations to showcase activity. We're going to work toward including other activity from the user like recent posts.
Update 11/13/13: We're now incorporating additional author activity into the sidebar, including posts written by the author, and posts where the author has participated in discussions.