What do you think?

[Theoryra]

it's an interesting idea, not sure if it would work, because you would have to have a pretty intelligent AI, and those never turn out well, and it has been done before, just not with npc's (vip games...)

Well, not exactly i believe. I know little about producing games and, what i know, i heard somewhere or saw in other games or figured out by myself based on what i heard. However, these npcs might not need a "proper AI", instead, they can all be scripted npcs, you see, just like it happens in most of the "scenes" from metro 2033, or so i heard. So every npc action can be scripted and some tricks can be used to avoid bugs or glitches, in other words, problems. The whole game would be scripted, even the fights (as long as the game doesnt require the player to interfer directly on the fight). Besides, this is a matter that, i believe, needs more discussion and time, but (despite of the fact i know little about making games) i'm confident that you can make the whole game scripted and, through tricks, make it runs smoothly.
You see, in the scene i described, every step, from the npc's behavior when hearing noises to the point where he asks you to stay and he goes to check somewhere else, can be scripted in a way that no "proper AI" will be required. Notwithstand, i believe that frictional have more than enough abilities to make the simplest AI to fill any gap that may show up.
So you may use some ai level or just script everything once the player will only watch the action in most of the cases (or at least, won't interfere directly).
it all depends on what you want to do. However, these npcs will be a little more useful than just monster killers, these npcs might be used to plant fear on player through its behavior and things he shall say. You see, fear is an interesting thing: in most of cases it spreads like an infection, however, it will require a focus (which in our case might be a npc) from where it'll spread to everyone around.
A interesting case that makes me believe on this "theory": while i was watching different "let's play" series on youtube, i noticed that there is a particular part on the whine cellar, when the game says to the player through a (simple) hint to turn off the lamp when an enemy is nearby, where most of people i watched panicked because they thought there was an enemy nearby, all because that hint said so. You see, that hint was the fear's focus, and the same can be applied in my idea, but with the npc saying such things instead of a hint. The bonus in my idea's case, is that everything would be reinforced by the npc's behavior displaying his own fear and tension.
An extra idea here, that can be brought with this npc protection thing, is a system where you may move the mouse up and down to say "yes" to any npc question and move the mouse left and right for "no". Considering that frictional second these "natural interface" system, it might fits well with the introduction of these npcs. (actually i'm suprised that they hadn't implemented this system of response in their games yet, perhaps they tried but something went wrong?).
And mind you if i ask what is this "vip game" you spoke about? Never heard about it, not with that name at least.

It seems to me that at the core of this is the tactic of giving the player a sense of protection, then ripping it away to create fear. A situation that the player can breeze by normally would now give them pause.

It wouldn't even have to be an npc. Maybe a bright lantern you carry wards off monsters. You would be able to see them running away from the edge of the flickering light. Then suddenly your lantern starts to falter... Big Grin

Indeed, however, it's not only to rip the peace off the player, it also gives the player some kind of "sanctuary", a point where the player can rest assure because they're safe for now. However, it can be used against the player as well, a way to get some extra fear points, by surprising them.
And, yes, it doesnt really need to be a npc, however, lanterns doesnt speak. You see, words are such a powerful thing, it can mould your mind and can be used as a weapon to increase the player's fear.

Well, i'm sorry once again for the long post, but hope you forgive me once i needed to made my point as clear as i could.

Obs.:Well, this idea is here completely for free, being a good idea or not, i'm giving it away to whoever whishes to use it, however, it would be cool if you talked to me about using it and perhaps metioning me in the credit of your work? Perhaps i can give you more ideas such as this one or, maybe, even better ones.
Anyway, i'm sharing this, do what you think that is right.
e-mail for contact: rock.your.bones@hotmail.com