Suppose that resolving combat challenges took the same amount of real time as is taken (in 3E) resolving a Diplomacy check or the discovery and disarming of a trap. In that case, there would be no need for all classes to be balanced in combat, and the notion of "taking turns to have fun" would work.
D&D, however, has always had very distinctive and elaborate rules for resolving combat. Therefore, combats take a lot of real time to resolve. As it sucks for a player to be irrelevant during that time, all character classes must have something meaningful to do during combat.
As long as combat is time intensive and other tasks are not, it is also important that combat abilities be balanced against one another, and it is natural for non-combat abilities be treated separately. And as far as non-combat is concerned, it can still be about "taking turns to have fun".
But 4e seems likely to have elaborate mechanics for challenges that are not combat challenges - the main categories I can think of here would be traps, environmental hazards and social challenges, but I'm sure there are others. It therefore becomes important, if this is the case, that no character be irrelevant during the resolution of these challenges - because that will suck for the player. Therefore, 4e needs it to be possible for any class to contribute to any of these sorts of mechanically- and real-time-intensive challenges.
I don't think that siloisation of abilities is necessarily the best way to achieve this design goal. I think an attractive alternative is to find mechanics that put a given suite of class abilities to work in the context of different challenges.
Thinking about Fighters participating in environmental challenges, it is easy to see how this would work: their great strength and endurance would enable them to plow ahead where others would falter (think Aragorn and Boromir on Caradhras). In game terms, their STR and HP give them a useful capacity to succeed at the environmental challenge.
Likewise, I can easily see how a Roguish ability suite can apply both to combat challenges and trap challenges. In either case, the ability to sneak around (therefore avoiding detection by foes, or avoiding pressure plates, tripwires and magic mouths), to move with speed and agility (thereby dodging AoOs, or swinging pendulums) would be put to work.
Some combinations of class abilities and challenge types are a little harder to see. How does a Rogue deal with environmental hazards? Or a Fighter with traps? I'm sure the designers can come up with something!
Fighters and social challenges are easy to see, however: a Fighter's physical and martial presence naturally create an impressive persona in social situations - intimidating if nothing else. It shouldn't be that hard to find a way to find a way to bring these attributes of a fighter into play within the context of social challenge mechanics.
I would actually prefer this approach to siloisation, for the following reason. Siloisation is likely to mean that the present distinction between combat mechanics on the one hand, and skill check resolution of other challenges on the other hand, remains. And skill check resolution leads to situations where only one character (namely, the one who has that skill) can meaningfully participate. SWSE-style skills can help with this a bit, but ultimately I think it would be better to generalise the mindset that "everyone should have something meaningful to do in combat" to the other sorts of challenges also, and I think this is best done without siloisation, and by designing resolution mechanics that draw on the existing attributes of various character types.
D&D, however, has always had very distinctive and elaborate rules for resolving combat. Therefore, combats take a lot of real time to resolve. As it sucks for a player to be irrelevant during that time, all character classes must have something meaningful to do during combat.
As long as combat is time intensive and other tasks are not, it is also important that combat abilities be balanced against one another, and it is natural for non-combat abilities be treated separately. And as far as non-combat is concerned, it can still be about "taking turns to have fun".
But 4e seems likely to have elaborate mechanics for challenges that are not combat challenges - the main categories I can think of here would be traps, environmental hazards and social challenges, but I'm sure there are others. It therefore becomes important, if this is the case, that no character be irrelevant during the resolution of these challenges - because that will suck for the player. Therefore, 4e needs it to be possible for any class to contribute to any of these sorts of mechanically- and real-time-intensive challenges.
I don't think that siloisation of abilities is necessarily the best way to achieve this design goal. I think an attractive alternative is to find mechanics that put a given suite of class abilities to work in the context of different challenges.
Thinking about Fighters participating in environmental challenges, it is easy to see how this would work: their great strength and endurance would enable them to plow ahead where others would falter (think Aragorn and Boromir on Caradhras). In game terms, their STR and HP give them a useful capacity to succeed at the environmental challenge.
Likewise, I can easily see how a Roguish ability suite can apply both to combat challenges and trap challenges. In either case, the ability to sneak around (therefore avoiding detection by foes, or avoiding pressure plates, tripwires and magic mouths), to move with speed and agility (thereby dodging AoOs, or swinging pendulums) would be put to work.
Some combinations of class abilities and challenge types are a little harder to see. How does a Rogue deal with environmental hazards? Or a Fighter with traps? I'm sure the designers can come up with something!
Fighters and social challenges are easy to see, however: a Fighter's physical and martial presence naturally create an impressive persona in social situations - intimidating if nothing else. It shouldn't be that hard to find a way to find a way to bring these attributes of a fighter into play within the context of social challenge mechanics.
I would actually prefer this approach to siloisation, for the following reason. Siloisation is likely to mean that the present distinction between combat mechanics on the one hand, and skill check resolution of other challenges on the other hand, remains. And skill check resolution leads to situations where only one character (namely, the one who has that skill) can meaningfully participate. SWSE-style skills can help with this a bit, but ultimately I think it would be better to generalise the mindset that "everyone should have something meaningful to do in combat" to the other sorts of challenges also, and I think this is best done without siloisation, and by designing resolution mechanics that draw on the existing attributes of various character types.