And the WBC doesn't have 'super' champions for unionified champs, but they do have their 'diamond' championships which go to winners of major fights at catchweights. I think Cotto/Pacquiao was the only one they had so far.
Cotto and Pac were fighting for the wba or wbo title and the wbc wasn't involved...but they wanted to be, so they made up some bullshit title and somehow convinced the fighters to give a % of their purse for the sanctioning fee (in addition to the one they were already paying for the actual title they were fighting for).
They also have 'silver' titles which is what they've done for #1 contender fights or just whenever they want to give a guy a belt even though he isn't fighting for a title. I think Morales and Canelo have wbc silver titles.
For the Marquez/Vazquez 4 fight, Vazquez refused to pay the sanctioning fee for the wbc silver title cause it was worthless and he wanted to keep as much $ as possible from his last big fight. The head of the wbc Jose Suliamon got all pissed off at him since he was the wbc champ for a long time previously and claimed it was a slap in the face to the organization that had 'supported' him for all those years they were charging him to be their champ.
Again, check out the articles I linked on badlefthook.com they're real good an explain some of the bullshit that goes on with sanctioning bodies.
Business of Boxing - Bad Left Hook - For Boxing Fans