EDIT: Video removed
Hopefully this link will last a while before getting taken down like the others. 40 minutes of Skyrim from Quake Con, although the audience is very annoying.
I can already see that I'm going to look for an interface mod once again just to make better use of the space, although its really cool how you can view items in the new inventory menu and zoom in and rotate them. Same with the books when you read them
There's lots of new detail in the world like fish jumping in the waterfall (that you can fish!) and the combat looks a lot better than in Oblivion (not that that's hard to do).
The Dark Brotherhood is back, awesome.
You can favourite spells that you like the most, I guess this makes them easier to access.
The skill tree, as you've seen before, is kind of looking up to the heavens and rotates aronud pretty fast (my concern was it would be slow, like every other side scrolling console menu I've seen, but I am also sure a mod can improve if not replace it all together), the constellation symbol for each skill is the perk tree for that skill that you zoom into. It looks really cool but isn't easy to quick reference.
The map is a gorgeous 3D rendering of the world and looks pretty awesome
Dialogue menu is similar to the inventory and magic menus, will probably need a mod fix.
The people of the world do a lot more things now, the game has caught up to the Gothic games in that regard. You can do those jobs for money too.
Horses are back the same as in Oblivion.
Snow is dynamic and placed by the game, not the developers.
Sneak attacks look the same as oblivion.
Duel wielding with magic is cool though I am not a fan of duel wielding weapons because its silly and impractical but whatever. Finishing moves are cool, and the magic effects look better than in oblivion (again that isn't difficult).
Sprinting has replaced running.
You can learn spells from tomes.
Video messes up at about 27 minutes and the audio is off, going faster than the footage.
A dragon picks up and flings a giant the player is fighting through the air.