What would even be point of that? I mean, one of core concepts of first PoE was that there are no class-specific attributes and every class can benefit from all of them, and you can see that systems were seperated - abilities, skills and attributes don't directly interact with each other. I guess that was develepers' idea to keep all of them seperated to allow for more interesting and diverse builds. I don't see reason to change it now, it worked pretty well.