To me, Skyrim is a amazing game with beautiful environments but like all TES games it suffers froma few faults that I feel, given new technology can be overcome.
1) Please no more start as a nobody destined to save the world nonsense, make us feel the game is much larger then the player.
A good example of how to do this would be to implement a war-like feel. Say the Dominion is attacking the Empire and the game starts with you as a Royal Guard in the middle of a Assassination attempt. Say that you are forced to flee your city with the Emperor's surviving family because the city has been sacked and now as one of the last surviiving high-ranked officers you are charged with rallying the troops. Something of this nature would be much more immersive and believable, which I think TES could use.
2) Dawnguard ROCKED for the dialogue between yourself and Serena. It was interesteing and she enguaged you where in the rest of Skyrim no one seems to give two flying @#$%s about you, they want you to do something and then they want you to go away. Serena's dialoge supported the growing friendship you two shared along your journey.
3) A more fluid/realistic combat system. A good example of this would be in battle have a good hundred+NPC's battling, giving the helterskelter feel of combat.
To enforce this I'd suggest having damage zones, if you take a arrow to the head and it penetrates your armor fully, you should die, no if-ands-or buts. You should be dead. If you block a hit from a warhammer and you're not a physical character your shield arm should be broken and you shouldn't be able to raise your shield anymore as well as suffering from reduced stamina.
Lastly to augment this would be a fluid, stylized battle system. A good example of this would be when a attack is incomming you gain a red arrow from the direction it is coming from and you have the ability to block/parry it with the proper command, even if we're not expert swordsman the game should feel like when we attack we are competent.
4) Skyrim especially suffers from being depopulated, we need more NPCs that spawn.
5) Dragons should be included in every game from now on but Dragons should be fearsome creatures that require a good dozen+men to take down. What's the point in a Dragon if a group of Forsworn can kill it?
6) a magicka/health/stamina system overhaul-if you run out of stamina and/or magicka and proceed to use a power attack or magic it should cost health to perform this action. We should also have human levels of health and stamina, making TES about group combat, because alone, YOU WILL FAIL.
7) Multiplayer. Not as in competitive multiplayer but as in cooperative multiplayer. Since the storyline wouldn't be based on "YOU WILL SAVE THE WORLD, GET THE GIRL AND BE ALL-POWERFUL" chiche you could have "friends" join your game who are at the same level of progression as you in the main story. There's 2 ways of achieving this, since hosting multiple of these would be costly and probably require a subscription. 1) follow Blizzard's battle.net 1.0 and have the players act as their own server or 2) have limited cloud computing between the player and his "friends".
Skyrim was a huge advancement but now that you guys have opened up the door to amazing things I want to see a home run next time. Just some thoughts froma avid TES fan.
P.S. I'd love to see something where a Daedric Prince is summoned into battle and the enemy has developed a Soul Gem ray and use said ray to outright kill a Daedric Prince. I love getting bombs dropped on me that make me feel like $%^& has hit the fan.