I learned something about mmo endgame last night from a single player flash rpg called Sonny.
At the beginning of Sonny (review here) you choose one of four available classes. As you progress through the game you level your character up with choice of gear and abilities according to your preferred playstyle. Then you hit the end game where the bosses have powerful skills and combos which must be countered in order to survive. Just as in an mmo the choice of tactics becomes much more limited at end game. You must figure out the trick to beating each boss and you have to employ it. Respeccing your character is essential (the game allows 5 respecs per calendar day). The character you have lovingly built up becomes unrecognisable as your favoured skills get thrown out to be replaced with whatever is required to solve the next puzzle. In truth you no longer play your character instead you play whatever role is needed to overcome the encounter. Sound familiar?
Character stats vary widely depending on chosen class so in order to ensure that every class can complete the game the critical end game skills are made independent of class. In fact every character has access to every skill but early in the game your choice of skills is determined by your character stats - strength based characters choose strength skills and so on. Endgame skills on the other hand are designed to be independent of stats and equally accessible to all characters.
I wonder if there is a lesson here for MMORPG designers. An often heard complaint about mmo endgames is that certain needed classes (typically tanks and healers) are in short supply while other classes are oversubscribed and unwanted in endgame groups. What if the really critical roles (perhaps tanking, healing and crowd control) were made equally accessible to all character classes. Got too many hunters and no tank - not a problem one of the hunters will enter tanking mode. I don't mean that a hunter will be able to perform a watered down half assed job of off tanking I meant that all of the tanking skills and abilities are independent of character class and the hunter will be just as good a tank as any one else.
It probably makes sense that a character who chooses to act in one of these roles loses their normal abilities for the duration to dissuade folk from soloing everything as uber tanked, self healing AOEing juggernauts. I can think of several ways to incorporate stuff like this into game lore e.g. a character who equips medical equipment must put down their weapons.
Another advantage of this approach is that there would be no need to have dedicated tanking, healing or crowd control classes which would allow for more creativity in character types. People who really like playing those defunct classes need not get upset. Even though any character type could play one of those roles not everybody will be equally good at it. I am sure there will be plenty of demand for specialists who concentrate on playing one of those roles to the utmost of their abilities especially for harder endgame instances.