No, MAD hasn't gone away. It's sitting on one side of a see-saw while "Making a Buck" (MAB) sits on the other.
Face it, most of the current good will between the US, Russia and China is based on money. If something should derail that economic train, the nukes will pop right back out.
Sure, there's been some disarmament during the last couple of decades. Now there are probably only enough nuclear weapons in the world to completely destroy it one time instead of the four or five times that could have been achieved in 1980.