Supernanny - Where are they now?

I just saw a clip of an old Supernanny episode on YouTube. I used to love it back in the day when my own DC were young.
Anyway, I got to wondering why there have never been any follow-up series, to catch up with what happened to the families. A lot of the original 'problem children' will be parents themselves now. I wonder if the families would be less than keen to take part? I wonder how successful SN's methods were in the long-term? Did she change families' lives for good, or was it a flash in the pan? How do the children and parents remember the visit and was the filming highly edited? I would watch it, would you??