This is very interesting. I might consider that there are narcissistic (though not clinically diagnosable) traits to codependency. However, the black/white thinking and categorization (including the A as "bad" and the Codependent as "good") could look a lot like some of the available diagnostic criteria of Borderline Personality Disorder. Pick another "disorder" and we could make the same argument about that diagnosis, too.
It will be interesting to hear about the next version of the Diagnostic and Statistical Manual of Mental Disorders which comes out later this year. We're no doubt ALL categorized somewhere in there, because "disorders" are on a spectrum. And that's a very big book...
Carry on,
posie