Just a personal preference, but I really want to see a few seconds of gameplay with a player sneaking up on someone and taking them out.
FO3 and NV trailers both had the same thing, guys just rushing into fire and unloading, please please please let us see the stealth mechanics!
Okay, silly plea done. Go back to rushing enemies in tons of armor looking badass.
Even if its a damn stupid way to play.

I also like to sneak

Stealth is a way of life. Sneaking better be a damn skill.

Do you really thing Bethesda would release a game that doesn't have stealth? I mean really?

But yeah, I'd like to see some stealth. Actually, I'd like to see an actual gameplay demo. You know, like the old times. I loved what they showed, but I kinda miss Todd just standing there PLAYING the game. And if he didn't play those old demos, I at least enjoyed his commentary while watching someone else do it. This felt more like a really long gameplay trailer than an actual gameplay demo.

I'm kinda hot or miss on making it a skill.
It was great to literally sneak directly in front of enemies at max stealth, but for the same reason I never went past 50 or 60 once I had the silent running perk. It kept me on my toes instead of making very hard seem like very easy.
Always had landlines laid out for when I was detected so stealth made the opening salvo much more effective, so it's probably a play style thing.

Now that they have a moddable Powerarmour, Id like to see an equally modded Stealt-outfit. It would seem illogical to only cater to one type of gameplay.

Most (all but one of my many playthroughs) have been Steath/crit based Sniper/Sneaky pete type toons. I personally dont like the attention it would garner, wearing a tank. I like to be able to skip the first law of the combat infantryman: "If you can shoot at them, they can shoot at you". I rather enjoy sitting at 300 meters out and picking the opposition off, one by one, whilst they wonder what the hell is happening and from where.

What would be a truly awesome addition to the stealth mechanic would be being able to distract enemies without giving up your position.
Never bothered with companions since the instant they were picked up, the enemy would somehow immediately know you err there as well, but that might change if I could send in my dog or companion to attack and continue to sneak around to flank.