Revisiting the "Holy Trinity" of MMORPG Classes
A feature at Gamasutra examines one of the foundations of many MMORPGs — the idea that class roles within such a game fall into three basic categories: tank, healer, and damage dealer. The article evaluates the pros and cons of such an arrangement and takes a look at some alternatives.
"Eliminating specialized roles means that we do away with boxing a class into a single role. Without Tanks, each class would have features that would help them participate in and survive many different encounters like heavy armor, strong avoidance, or some class or magical abilities that allow them to disengage from direct combat. Without specialized DPS, all classes should be able to do damage in order to defeat enemies. Some classes might specialize in damage type, like area of effect (AoE) damage; others might be able to exploit enemy weaknesses, and some might just be good at swinging a sharpened bit of metal in the right direction at a rapid rate. This design isn't just about having each class able to fill any trinity role. MMO combat would feel more dynamic in this system. Every player would have to react to combat events and defend against attacks."
You're looking for Runescape. It's designed so that you can fight using melee, magic, or ranged/archery depending on your preference of the day, and you can eventually master all three. Similar with non-combat skills. In fact a few upper-level monsters and bosses are designed such that to defeat them you must switch combat styles mid-fight by swapping out your equipment.
Alphanos
You are describing Shadows of Isildur, Armageddon and Harshlands. MUDs of course... Maybe you should try any of them and see if you enjoy it? Make sure you hang out at the bars at first though.
I think the jack-of-all-trades is not useless. They're very useful. A lot of MMO players don't see things this way, because they're playing a strategy game where all parameters are known, rather than an RPG game. Ie, they've done the same fight a thousand times, and know exactly what is needed to succeed. So they plan around having perfect characters who fit exact roles. Most of those games demand that you're always the best you can be, giving 110%, gear checks done before you're allowed to join the team, etc.
However in situations where the unexpected may happen, the hybrid character becomes much more useful. Noobs they'll say, some other group will have memorized that particular fight and know exactly what to do. But that's not everyone. Newer MMOs are being designed to attract more casual players who don't raid constantly, who spend relatively more time soloing, and who use almost exclusively pick-up-groups when doing group content. So thinking on your toes becomes necessary, and the particular role your character will fill may not be known until everyone gets together, and the role may change during the encounter.
Tank+DPS+heal is boring. Hybrid is fun. And yet in many MMOs the hybrid characters are looked down on or shunned.
The only MMO I'm playing now (and maybe the last) is Lord of the Rings Online. I've got a captain there, who is incredibly fun in groups. Not the best tank, not the best healer, not the best damage dealer. So it gives out buffs, but in some older more hardcore games that type of character would be dismissed as worthless in serious groups because it's not the best at one classic role. However having a captain in a group makes everything run a lot smoother. You can switch between several roles on the fly (no expensive respecs needed in advance), doing what is necessary at the time. A bit like Druid in WoW, except that in WoW the high end groups would still demand that you pick one role, spec for it, then stick to it (boring).
Look at games like City of Heroes or Champions Online too. The traditional roles can be done, but it's not necessarily the best way to go. Naturally of course, since players will want to be superhero archetypes, not fantasy archetypes in tights. For instance, a defender type can have a "healer" build that directly repairs lost health, which a lot of new players from other MMOs try out, but it's not necessarily the best way to defend the team (preventing damage with debuffs or force fields tends to be more effective than repairing it afterwords).
The whole EQ style of tank/dps/healer is old and creaky and needs fixing, along with the idea of "aggro". You don't see this in most single player games. The tank as a high-armor but low-damage guy with aggro is an MMO invention.