At the end of the day, if it gives people more motivation to do better, more effective workouts then its not exactly a bad thing. A few gym snobs always think they know best but who cares. I got lucky to have a rowing coach who would do weights coaching with us and am quite good at self motivation (not a problem now that I've joined a rowing team again) but to those who haven't had that I can see the benefits in joining something like this.
Rouge - looks like its not just a diet, but an actual workout schedule. Its a fad as there are benefits of doing high intensity exercises with weights and the company has done a good job of marketing it.
Don't think I'd join something like that, but in no way think its a bad thing to come out.