A question about subclasses and masteries

With riot trying to lock down the champs into subclasses, I have to ask if we'll see a new mastery system with 1-2 generic lines and 1 line per subclass your character qualifies for? For example lil' Koggie is both an ADC and an Artillery mage so he'd see both the generic lines as options as well as the ones for ADC and artillery mage but nothing else. I think riot doing this would help define the classes (more unique feel via specialized masteries) and then better define the champs as a diver/skirmisher is going to be given different a option than a diver/assassin. Both champs would be able to go into diver, but one would have the option to go with the assassin masteries and the other would get the skirmisher masteries.