The problem I have with Skyrim's difficulty setting is that the only thing it changes is numbers. Combat in Skyrim is not all that strategic. You're either sniping enemies with a bow before they detect you, or you're trying to reduce the enemy's health to zero before they can. In the latter, it's just a battle of numbers. Changing the difficulty just feels artificial.
I think the series could use an overhaul, adding more strategy to battles. Add a dodge button. Make enemies more intelligent (magic enemies and bowmen trying to keep their distance from you, for example). Add more variety in defensive spells, like a light spell that temporarily blinds enemies, or a shockwave spell that pushes nearby enemies away from you, or a shield spell that grants protection from melee damage if you activate it just before being hit. Make night eye actually useful. Allow players to eliminate sources of light, activate night eye, and slaughter them while they're confused (enemies with night eye, torches, or light spells would still be able to see you). Make poisons more potent, and last longer than just one hit, unless it's an arrow (although retrieved arrows could still be poisoned), but make it a crime to use them against non-evil characters. (Real life poisoned blades were considered taboo in medieval times.) Mods do some of these things, but The Elder Scrolls could do so much better with its combat.
Edit: Oh, and stealth can be improved too. Right now, it is yet another battle of numbers, where crouching with a high sneak ability can make you essentially invisible to enemies looking right at you. In The Elder Scrolls Online, you can sometimes wear a disguise to blend in with the enemy. Bring that in to the main series.
