Originally Posted by Bashiok

We're looking at most players having an average of six "active"skills, these are your magic missiles, frost nova, electrocute (to use a few wizard examples), and because you're not just pumping up one single skill - and thus one single damage type, immunities become far less relevant. We're not going to do away with resistances, they still add something, but they're likely to be toned down a bit.