I don't know, I had fun with stealth in STALKER. It had none of that "I'll think that the armed guy I've looked at for full 5s was just a rat" nonsense we had in Deus Ex, nor "whatever killed two other guys and shot me in the ass was probably just wind" we've seen in TES: IV-V.
The only problem was that it was not really obligatory at any point.
Skyrim could defnintely use some longer (as in indefinite if you're still in the location) and more thorough searching, otherwise it turns into "shoot, run, hide, wait for AI to give up, repeat" exercise.
I think most people just don't want to be punished for their mistakes so endlessly. They want that 10 second reset so they can be sneaky again.
I think most people are morons.
I also think "want" and "enjoy" are two completely different things in games.
Shoot-hide-wait-repeat loop can't support enjoyable gameplay. It's just too fucking derp - you do exact thing, in exact same place, waiting somewhere around a minute every iteration 'till you run out of targets.
Good stealth mechanics shouldn't work like that. Good stealth mechanics should involve several alertness levels:
1. normal
2. suspicious - investigate, something suspicious just happened, but not necessarily something that can't be blamed on natural causes (slight movement noise, glimpse, missing object, comrade missing for a short time)
3. alerted - active search, something happened that can't be blamed on natural causes (loud noise, projectiles, attacks, people disappearing, corpses, too much suspicious events)
4. alerted suspicious - like 2, only while already searching for player, treated more seriously
5. contact - player located, lock and load.
2 and 4 are short term states and can be handled by single separate flag.
Elevated alert states should propagate from NPC to NPC on proximity, and once alertness level rises to "alerted" it shouldn't fall below it unless player leaves the location for prolonged amount of time and it gets reset or partially reset (or unless the likely culprit gets eliminated via kill, capture or escape, so getting a stealthy follower and having them visibly run off or letting them die by enemy hands should - after certain period - reset the AI to normal).
Also, attacks, bumping, manipulation and other forms of interaction should propagate the instigator's id to inanimate objects (and from objects carrying such id to further objects), so, for example, bowling guards with explosive barrels should count as attack.
This way there can be tradeoff - do I kill this guy using element of surprise, knowing that it will increase chances of detection in the long run, or just ghost by? Do I create a distraction or try to not attract attention? Etc.