1. Mod tools at least comparable to TES Construction Set.
Bethesda has always supported their modders above and beyond the call of duty, and I would love to see that continued. Mods were the best part about Morrowind and Oblivion, the fact that you could add things that you wanted to your gameplay experience and remove that which you didn't like. If the modding tools are removed, I will be extremely angry with you Bethesda... and you won't like me when I'm angry (sry guys, go ahead and throw your tomatoes.)
2. Vikings.
Norse culture is always something that I've wanted to learn more about, but never got around to. It all seemed pretty bad ass, and with good reason: Viking *ARE* bad ass. From what I've seen in the trailers, those Nords are going to be a helluva bunch. I want them to drain mead tankards while they sail their longboats to pillage the coast of Morrowind or something. Perhaps we can have a raid side-quest where we can visit a city from another ES game or something, but instead of visiting we burn the whole thing to the ground and pillage?
3. Dragons.
If you're going to put in dragons, don't think your going to get away with not including pets. I want a dragon for a pet. When my neighbors dog wont shut up at 3AM, and I am trying to fall into my mead induced stupor until morning, I want to be able to say "shut that stupid mutt up dragon". Then I want to wake up the next morning with a pile of ashes in my neighbors yard. Not only that, dragons are [censored] awesome. Do you think some highwaymen are going to [censored] with me if I swoop in riding a dragon? I didn't think so. Perhaps there can be some cave in the top of some mountain that is a known dragon roost or something. One that can only be reached by flying or something, and inside is a dragon egg or something. Raising my pet dragon from an egg will be far more rewarding to me than just capturing a live one or something, hopefully I can tame a live one too. That would be interesting as well.
3 ( b ). Pets in general
Yea, I would like to be able to tame any creature. From wolves or mountain tolls, to mudcrabs or rats. Hell, throw in some eagles or hawks as well. Birds are bad ass.
4. Vampires.
The vampire clans and factions were great in Morrowind. Bring them back for Skyrim. The Oblivion vampire clans were non-existent and being one was so boring it made me fall asleep, dream about how boring the vampires were, and then bore myself awake. I don't want no sparkly vampire either, they need to be evil carnivorous death machines driven by a natural lust for blood that if left unchecked, will eventually overpower their humanity.
5. Werewolves.
see vampire section except I don't see werewolves being in clans so much as packs. Perhaps some in the cities who struggle with being werewolves and try to continue with their normal lives, a clandestine group of werewolves who want to turn everyone else into werewolves and take over the humans, and wild ones who have abandoned humanity completely.
You should have state sponsored werewolf hunters who hunt wild ones and ones that are trying to live as werewolves in secret. There should probably also be a state sponsored place where registered werewolves, people who are infected but want to live normal lives, can come every full moon and be locked in a room or something.
6. Necromancers
I want to have to have the option to become a necromancer. It's a viable character choice I think, and one that should definitely be included.
7. Dorfs
I am not an ES lore buff, but I know that the Dwemer are basically dead. Can we get a dwemer ruin or something like those in Morrowind? Hopefully there might be something even cooler than ruins like, the last dwemer city or something. Look at DAO or Dwarf Fortress for dwarves done right.