Actually, IMO AA is a bit closer to a religion than a cult, the word "softer" cult seems fitting, but for all intensive purposes, reading the 12 steps seems more like a conversion to the christian religion than to recovery from substance abuse. IMO AA has little to do with recovery, and more to do with converting the weak and needy into full blown Christians. I see it more as a modern day religious crusade.
However, seeing as IMO religion is as well a "softer" cult, I think they should ALL be considered to exist in the same category. Just remember that the definition of a cult is not evidence of abuse, its the existence of tactics of thought reform, "group think", isolation from the outside world and a systematic push for more conversions.
Both religions, AA, Behavior modification programs (and their seminars) and registered (abusive and non abusive) cults all operate on a similar system to control their followers. So how do we really separate the like from the like? I believe the best way to do that is to put these institutions on a sliding scale of cult-like severity because in every one of these groups there is the good things that make them a service to our society and the bad things that relate them to the reputation of a cult group. The problem is that the word "cult" has such a bad connotation that no one wants to accept that their group is in its conception very similar to the way that a full blown cult operates. From what I can assume, cults must have snagged their system model from religion, or in my opinion, cults are just the small business versions of religions. I guess for some, things just went completely wrong, but apparently making up your own rules on behalf of an all mighty higher power really gives you a lot of room to go nuts, and many of them do. So maybe the word cult would refer to those institutions that would be at the bottom of this sliding scale, but lets be honest here they all swim the the same pool.