It was suggested on the WotC forums that I repost this here, on ENWorld. So, here is what I said in response to the mirror post on that forum:
As with many others, you are fixated on the name, and on the Points of Light and Forgotten Realms fluff for class names. 4E is very specifically designed such that mechanics are more important to game balance and structure, overall, than fluff. The fluff is instead extremely variable, and not tied in directly to the mechanics in a way that isn't incredibly easy to alter without harming the structure of the class.
A Fighter is not ACTUALLY called a "Fighter" in the game-world itself. They are called Thog, Warrior of the Eleventh Tribe of An'tel, or just, "warrior". They are Sir Balthar Truefate, Exalted Knight of the Golden Vine, or just, "knight". They are Sharanna Giltleaf, Swordmistress of the Sacred Vale, or simply, "swordmistress". They are Grell Frostbeard, Soldier of the House of Frostbeard, Scion of the Mithril Anvil, or simply, "soldier". They are not Thog, Sir Balthar, Sharanna, or Grell, "fighter".
On Athas, for a more direct example, Wizards, Sorcerers, Warlocks, and (if allowed to be present by a DM) Artificers are ALL either a preserver, or a defiler, depending on how they choose to draw their arcane magic from the world. Rather, those are all different mechanics representing different paths taken by characters who, in-game, would be considered ONLY a "preserver", or a "defiler". They would not be called "wizard", or "sorcerer", or "warlock", or "artificer" by the residents of the world, except in the vague sense (i.e., "I despise all of you d***ed sorcerers, be you preserver or defiler."; That statement could very well be directed towards a character of the Wizard class.) The actual act of defiling, with the way 4E is set up, is more likely to be a series of feats that allow anyone from an arcane class to gain extra power in exchange for destroying part of the world each time they do so. There is absolutely no reason why there should be a need to, and plenty of fluff-reasons NOT to make a distinct class called, "defiler", or to make a preserver and defiler version of each of the arcane classes, or, worse, to ban all arcane classes that aren't either Preserver (Wizard?) or Defiler. Anyone who draws magic, arcane magic on Athas, from the lifeforce of living things (primarily plants), must choose how they draw said power.
Psionics, too, are far more likely to have crossover fluff-wise. Members of the Order aren't all going to be Psions. Some will be Psions, others Psychic Warriors, others Mindblades, or Erudites, or Ardents, or whatever names are chosen for the 4E psionic classes. The same holds true for all of the academies of the Will and the Way located in each city-state, or present in each village or slave tribe, and so on. None of them, however, will be addressed by those class titles. Rather, they will ALL be powerful users of the Way, and addressed as such in-game, even though they come from a wide variety of classes. They will be referred to as masters, novices, apprentices, adepts of the Way, as telepaths, and so on.
Expanding that such that most of the primal classes are likely to be addressed by the populace as "druid", and tied in to the primal Spirits of the Land, meshes very well indeed with Athasian lore. Even within the lore, some druids are more likely to focus on air (control?), or fire (damage?), or water (healing?), or earth (buffing?), or some combination thereof. However, you will not have a character who is at the top-end of skill and power in all four elements, save perhaps at the epic tier. How each such person manifests their mastery of the elements will not be in precisely the same manner. Two air/fire "druids" could very easily focus on QUITE different uses for just those two elements. On top of that, you have their ties to the Spirits of the Land, and those ties too will differ for each and every character in the game world, each focusing on their own unique combination of specific manifestations of that link.
A "Shaman" doesn't need to have a "ghost, wraith, insubstantial thing" for a companion. There is zero compelling mechanical reason for it to be required to be such a thing. It is nothing more than fluff, and is entirely mutable. It might be a wisp of air, or the earth rising up into a humanoid shape awash with roots and moss and plants and so on, or thousands of insects swarming, small animals from all around tying up key areas, a blazing ball of fire like a miniature version of the dark sun itself, a being composted of air, earth, fire and water in an ever-shifting variety, or any variety of window dressing to describe what is mechanically the Shaman's "Spirit Companion".
Having come from an extensive background in HERO System (in addition to D&D since BD&D), it distresses me greatly to see so many folks allowing themselves to get so hung up on particular fluff, when that is the single least important aspect of the system itself. The fluff for a given world is certainly important to the FLUFF of that world. In that regard, 4E fumbles, not in the mechanical structure itself. They have still tied, at the very least in the minds of a multitude of players, mechanics and fluff too intimately. Mechanics are mechanics, and should be mechanically balanced. Fluff, flavor, campaign information, however? No. No way. Just because Wizards of the Coast calls a Cleric a "cleric", does NOT mean that in a given campaign that any and all characters who likewise choose the Cleric class should follow even a fraction of the fluff WotC placed in the Cleric entry. Fluff they placed to make their specific game worlds, be it the Points of Light setting, the Forgotten Realms setting, the Eberron setting, or whatever other world(s) they release, interesting worlds to play in. Nothing more, nothing less. They've even explicitly said so, repeatedly, in both the PHB and the DMG, strongly encouraging not only changing fluff around at-will, radically altering entire descriptions of any and all powers to suit a given theme, they've even gone so far as to say that changing actual DAMAGE TYPES on powers is perfectly acceptable, yet will not decay the system's integrity.
