In an effort to better integrate with Google+, Reader is retiring friending, following and shared link blogs. That means the social features in FeedDemon that rely on Google Reader will eventually stop working.
They won't stop working right away, though. Google will continue to support those features in its API even after they disappear from Reader's UI. But at some point (I don't know when yet) they will cease to function, and you'll be unable to share articles in FeedDemon or follow the shared articles of other users.
Before that happens, I'll release a new version of FeedDemon that removes those features. But I won't do that until the new Reader goes live and I have a chance to test against it, which will likely take a few weeks.
I am, of course, disappointed to see those features disappear. I know a lot of FeedDemon customers will miss them, and I'll personally mourn the loss of shared articles since that's something I use every day.