Since we"re still on this subject.
I"d like to see someone try to emulate EVE in its method of giving you a temporary role based on your equipment. In EVE it is your ship and it"s fittings that determines your role. Surely inventory management and current equipment could emulate that. Guild Wars has a slightly gay way to lock you into a specific direction for a mission by preventing you from accessing spells that you didn"t add to your hotbar before the mission. WoW is halfway there. There is differing gear even for the same class based on your role. The only things standing in the way of WoW being based solely on equipment are talents. Talents provide a very powerful corollary for your equipment which encourage you to follow one path and all but ignore the others.
Perhaps my character is well versed in all kinds of physical combat, and by bringing the right equipment I could either backstab and gouge my opponents with agility or use a maul to crush their bones with all my strength. Make it so that I have to switch most of my gear to be effective in using a different set of skills to augment an entirely different weapon. Then you have people who have preferences, their class, to which they are very well attuned, but can adapt to different situations and environments given the proper preparation.
This would require ancient concepts like encumbrance to be emphasized. The rogue skills would be heavily penalized for carrying around extra weight in the form of a maul and chainmail. And with the heavy weight of the base gear to be a heavy fighter, carrying around rogue gear would preclude you from obtaining any treasure. Besides, if you did later switch to rogue gear you"d run into the penalty mentioned before. It would be wiser to carry around items that relate to your current role and perform complete gear swaps at a bank/stash area.
If you could do it right you could have a combination of classes and derivative skills, which define specialties, but it would be an inventory meta-game that determines how many choices you have at any one time. I"m sure we would all really enjoy farming necessary offspec loot and finding places to put it.
Everyone gets the illusion of choice at the same time that classes are well defined for the benefit of high end PvE design. You aren"t freely designing your own class, you"re following the prescribed route set by the developers. They could also, then, design events that render huge sets of skills unnecessary without them also rendering players unnecessary as they have some limited options to change. This would be similar to fire-immune mobs that mages have changed spec for, with a slightly different flavor of gay.
Furthermore, as the game progresses you can add additional skills and equipment to effectively create new classes like a "berserker" or "death knight" or whatever. You don"t need to make sure your new class has an individual role in raids, is balanced in PvP, etc. You might design a few events to benefit from your new skills which would encourage, but not require, players to employ them.
I"ve got a running theme of gradients rather than boundaries.
I"m more interested in the creation of sandbox social atmospheres. I like slaying dragons, I do. But I"m more interested in crafting and trading. I don"t think the emphasis on non-combat classes hurts combat either. Especially in a PvP atmosphere, this means that the people you run across are less likely to be able to defend themselves against you. Gatherers, crafters, traders, etc. are all less well equipped to fend off an attack, giving you an advantage if you"re an "adventurer". This opens the door for the existence of pirates, a.k.a. griefers.
I play the successful combat-oriented MMOs because I disagree with most PvP game designers to a fault. I think they"re all wrong, they focus on the wrong shit (1 on 1 combat), etc. Whereas in PvE the epitome of combat is raiding, in PvP it is often 5 on 5 combat. Larger fights either don"t exist because there isn"t anything worth fighting for or they break down due to lag. At the least EVE has siege equipment (capital ships) that lack power in a 1v1 fight, unless those individuals are piloting siege equipment themselves.
I"m paying some attention to AoC and WAR, but I don"t think they"ve got the sandbox atmosphere at heart. Crafting and Trading will be the bitches of Combat and I will once again become bored after I slay the dragon because the dragon doesn"t respawn for another 4 days