For a start, headbobbing, panting running. Is this going to be in, do we think? Personally I would love it, but it looks far too... perfect to be gameplay.
If it was possible for several 2005+ action games, it's possible for a 2011 RPG named Skyrim as well.
Secondly, hands visible in first person. The bit where he stops at the cliff- thats some nifty edge detection right there, and a good animation too.
For todays technology, it's just a little better than the best stuff in Oblivion, as it should be. Just look at the muscle detail on the arm of that hunter in one of the screenshots.
Thirdly the animations of dragon fighting. I know the burning of the ground is confimed but Come on, unless bethesda really is that awsome, that can't be what dragon fighting is going to look like.
If the first Fable game (Lost Chapters), Half-Life 2 (the Combine aircrafts) or several Final Fantasies can pull it off, allbeit at much lower model details etc, then I'm sure it'll be possible in Skyrim as well. The problem is that we've only seen glimpses of it. I don't see how anything in the video cannot be in the game, it looks great but that's because Bethesda is running the game (and the video recording) at MAXIMUM video settings with top notch computers. Resolutions, object detail/load, lighting, particle effects, physics and everything is running at their absolute values.
Skyrim allegedly gives us greater camera control in 3rd person and the video is, after all, a montage of several individual gameplay moments as well - combining 1st and 3rd person views and showing off the best recordings of likely 100s of hours of gameplay into a small video.
Don't worry, it'll all be in.