One of the biggest concerns with Diablo III's class differentiation concerns the issue of mobility. Besides putting one foot in front of the other to pace about the world of Sanctuary like enthusiastic tourists, characters in D3's predecessor, Diablo II, had a variety of different ways that allowed them to get around with varying degrees of ease, thus raising the problem of unfairness.
Blizzard community manager Bashiok chimes in on the matter.