it seems to have something to do with an improvisational style of DMing and tailoring encounters to the PCs.
That's not a bad approximation to start with.
4e has a lot of features obviously inspired by indie games. "Pemertonian scene framing" (not my phrase, by the way - I've always been clear in referring to the games/designers that I learned the approach from) is an approach to 4e that draws on those features, and pushes them a bit harder than the 4e designers explicitly mention (though the DMG and DMG2 already push in this direction), by drawing on advice in other relevant games like HeroWars/Quest, Burning Wheel, Marvel Heroic RP, Maelstrom Storytelling, etc.
The "Permotonian" view seems to be that a game is basically a sequence of fights (fight A, fight B, fight C) that have been pre-ordained. The context of each fight is re-skinned on the fly by the DM based on player actions, while the content of each fight is re-skinned by players on the fly. In a way, "narrative control" reduces to who has power to re-skin what.
That's not accurate.
First, the elements are not "fights", they're "encounters/challenges" (in 4e terminology) or "situations" (in Forge terminology). These involve conflict, but it need not be violent conflict. Second, and more important, there is no pre-ordaining. That's the whole point. Re-skinning has very little to do with it - there's actually very little of that in my game. (Not that I've got anything against it. But generally I like the 4e flavour text.)
Hence "narrative control" is not about who can reskin what. It's about who gets to decide what the shared fiction inclues, and hence what the game is about.
Fictional positioning means resolving a scenario without recourse to the mechanics
That's not how I use the term - my use is influenced by Vincent Baker use of it on his blog. By "fictional positioning" I mean that the shared fiction matters to resolution. Your description would be a subset of that, but not the whole thing.
An example which fits your description of fictional positioning, from White Plume Mountain: the PCs come to the frictionless corridor with the super-tetanus pits and the players wonder how the PCs can cross it; they decide to surf across on doors; they therefore have their PCs go back in the dungeon, unhinge some doors, bring them back and describe their surfing. In AD&D, at least, that could all be resolved without engaging the formal mechanics: that would be resolution by pure fictional positioning.
But you could imagine putting in a couple of checks - if the doors are well-engineered and the PCs don't have tools, maybe a STR or DEX (or even INT) check is required to unhing them; if the GM thinks the door-surfing is hard, maybe DEX checks to see if it works. The fictional positioning is still crucial though ("We're in a dungeon with doors that can be unhinged; doors are big enough to surf on if you slide them across a frictionless surface; etc").
I don't think 4e makes fictional positioning especially important - as the WPM example shows, fictional positioning is front and centre in heaps of classic D&D, for instance. Rather, I think 4e raises some distinct challenges in relation to how fictional positioning works in the game. Those who say 4e's just a boardgame - ie a game in which fictional positioning doesn't matter, and it's just rules vs rules that never touch the "story" - have noticed the challenges, but haven't noticed the various ways in which 4e resolution does depend upon the fictional position of the PCs. (I won't elaborate here - I've debated it a day or two ago with KM in the current Legends & Lore thread.)
In my experience, that was far more common in BD&D and AD&D, where the rules covered less territory (and were often so jumbled and incoherent that fictional positioning was the only way to make sense of them). 3E and 4E have much heavier, more comprehensive rulesets.
Agreed, as per the above paragraph.
As I see it, one difference between 3E and 4e's resolution systems is that the 3E system takes more input, at various points throughout resolution, from rules elements/descriptors that are direct expressions of the fiction: eg in a trip attempt we ask "How big is it?" (answer comes from rules, but these read off the fiction - eg a 10' tall ogre is Large), "How many legs does it have?", etc. And if someone notices an element of the fiction that seems relevant, but that the formal mechanics don't pick up, they're expected to factor it in (eg via a circumstance modifier).
4e's mechanics are more formal and in some ways more closed, but that doesn't make the fiction irrelevant - it feeds into framing (eg what keywords are in play); and the narration of consequences, which then feed into future framings.
Well, the problem with that is that in some cases, inclusion of Element X necessarily excludes Element Y.
I think this is right, although those connectins/exclusions aren't always obvious just to reflection and inspection.
But it's because I agree with you on this that I have doubts about how D&Dnext, on its current trajectory, will deliver a 4e-style experience.
What would be an example of a PF-ism that you think merits such scrutiny and isn't receiving it?
My take on the 3E/PF vs 4e issue - to the extent that that's a useful way of framing is this:
I see heaps of posts attacking 3E/PF multi-classing, overpowered casters, fiddly/useless skills etc. The counterpart of these attacks wrt 4e are things like multi-classing feats being too limited/expesive, hybrids being potentially broken, feat taxes, the bad stat scaling which also makes the skill system less smooth than it could be, etc.
I don't know whether PF players get upset by those posts (the main ones that I notice seem to upset them are ones about caster dominance, and related posts about the 5MWD - but that's just my utterly unscientific observation). I don't get upset by those 4e criticisms - in fact, I think many are warranted (although I don't think the feat tax thing is such a big deal - I play without expertise feats in my game - with the exception of Superior Will!).
The posts about 4e that do make me respond with irritation and/or frustration are the ones that tell me 4e is not really an RPG because (i) it's a skirmish game, or (ii) it ruins immersin, or (iii) it lacks verisimilitude, or (iv) it has too much metagame, or (v) it neutered the GM, or (vi) it lacks meaningful fictional positioning, or . . . And I personally don't ever recall seeing a post telling PF/3E players that their game is not an RPG.
The reason those posts irritate me is because they are ignorant - they display a complete lack of familiarity with the past 15+ years of RPG design (including but by no means limited to The Forge) - and they are rude. It's just rude to tell someone posting to an RPG board, talking about RPGing techniques and experiences, to tell them they've got their own self-understanding so fundamentally wrong.
