Well, the way the powers system works, is that while a lot of archetypes are covered in the base classes through phb1-3, is that the front loading is what changes. And role mechanics, and how wacky you get with that.
- Like a ranged defender?
- Melee Controller?
- or weird leaders?

Classes it seems are notoriously difficult in 4e, most due to the 70+ powers you gotta make to even contemplate making a single class. Anyway, I feel that at least the 4e folks here at least try. At other boards, it's more or less a lost cause.