Overall depth.
Skills
Attributes
Spell creations and our old spells
Variety in weapons and armor/clothing
Interesting quest, deep and engaging quest, the quest as is are to short
The cities are to small
To few factions to join
What he said plus:
Fast travel via carriages would be enough.
They could have put more work into bard's collage - give it a proper meaning. I love bards in fantasy games - as a combat style. The game have the needed skill tree's to create somewhat of a bard, but since they actually put in a bards collage they could have implemented a few other things. Like a non-combat tree called Entertaining or something.
No level scaling - being able to go where you please at any point in the game becomes more interesting if the content don't scale with you. Makes the world feel more dangerous.
Atheletics and Acrobatics. I would like to build some characters very athletic.
Combat could have been more advanced with todays technology. Same with pick pocketing, RNG? in 2012?
Their older games where more in depth so simple combat design,rng etc didn't matter. Skyrim is less deep and has got pretty much no learning curve, so they should have improved upon other things instead.