I don't really understand where you're coming from. Skills are task resolution mechanisms in 3.x and 4e. (In fact, with a few minor changes, they are the same task resolution mechanisms.) The major change from 3.x/4e to D&DN is that the task resolution aspect of skills is moved from the skill rules to the attribute rules. Instead of swimming being a skill that defaults to strength, swimming becomes a strength check where the swimming skill provides a bonus.
This has some significant advantages in DM flexibility (e.g. a Con-based swimming check where appropriate) and modularity (e.g. the basic version of the game can give a class a bonus to stat checks instead of skills), but I don't see how that qualifies as a change to a "plot bennie" system.
-KS
Struming a lute through the ages (I'm omiting editions I'm not familiar with)
2e: It's an action allowed by the musical instrument (Lute)NWP, sometimes a proficiency check is called, it is keyed of Dex. You get betterby investing extra slots
RC: It's an action allowed by the music (strings) skill, sometimes a skill check is called, it's keyed off Cha. You get better by investing extra slots
3.0: Somewhat foggy, it is fluff most of the time. The rest it is a Perform (Lute) check, you get better investing more skill points and by using Skill focus feat, a masterwork instrument helps
3.5: It is a normal action, althought a Perform (strings) skill check is defined as a way to gain money, you can get away with using perform for many things more than just earning a penny, the skill still is the mechanical reflection of struming the lute, it's keyed of Cha, you get better investing more skill points and by using Skill focus feat, a masterwork insatrument helps.
4e: It is just fluff, the actual mechanical used will vary depending on purpose and effect (Want to soothe? use heal, Want to please? use Diplomacy, want to distract? use bluff) and it is entirely equal to you just outright using the skill for the effect.(In fact as far as I know this is highly theoretical, I've never been able to see it roleplayed this way) You get "better" just by existing, you cannot really be a good lute performer, except by proxy, the only explicit description of a lute being strumed is with certain bard rituals which relly on Arcana, so in a way Wizards are the best lute players on the world
DndN: As of this packet, it is a Dex check -most of the time- the actual skill is just the right to randomly be better "between 1 and x", however the existense of the skill gives an insight on how it is supossed to work. You get better just by existing, and the amount is basically random, so there is no sense of improvement with it, skill focus just makes it a little more reliable. So the skill is a thematic plot bennie.