I have or currently use just about every link on your list - or at the very least have them in bookmarks...except for Dead Followers! HOW COOL! I just checked it out to see how many "true" followers I have. Only one question about it. I know it documents when the "dead followers" last posted but does that mean they're really "dead"? I think some of them only curate content.
To @mynameisbrian - is that something that might be added to your awesome site?