The origins of D&D's class roles

Back in March Dave Noonan (on his blog) posted three articles on the origins of 4th Edition's class roles, i.e. defender/leader/striker/controller. We are all more than familiar with the "4E is the pen & paper version of World of Warcraft" jargon, but how did WoW develop their roles? Where did it all originate?

Dave makes the delve into the history of the game and does an excellent job of showing the evolution of class roles in D&D and how we got to where we are today with 4th Edition. If you haven't checked them out yet I highly recommend giving these a read:

So where did these roles come from, anyway: An Intro

So where did these roles come from, anyway: Part 2

So where did these roles come from, anyway: Part 3