Just for what it is worth.
I have heard that Airbus have said that, initially, they will only train people with previous A340 experience, (possibly A330 too, not sure), onto the A380 if this type is new to the company buying it and the training is being done at Toulouse.
This is definitely the path being followed by one major Far East carrier. EK, who are buying a lot of airframes, may be able to get Airbus to change this policy, if they want to or it may suit them just fine. It would seem likely that current A340 crews are probably going to be first onto the A380.