Based on what i have played thus far i can only muster together a few ideas that would be worth while and these could easily be invalidated with further playing

Restoration of Helgen
expansion of Winterhold (both the college and the ruined city)

more miscellanious quests
over taking the thalmar

then a saints tale rebirth

and possible expansions and tweaks to make dawnstar more unique and interesting of a city

I offer my idea of a Hidden Village which I believe is lore neutral. A group of refugees hide out in a hidden village to escape the war going on. A lot remains to be developed.
1) How is the village hidden?
2) Why is the Hero there?
3) Quests.

The original idea of a mage/necroancer who demands the sacrifice of a warrior or adventager does not work well in my opinion. This is a mod and the Hero cann't sacrifice himself and a substitute seems too obvious and boring.

There is plenty of space and the suggestion has been made that it could be in a dwermer ruin. Farms would be needed as well as the normal village with various workshops. Mining should be easy. Scripting would be important.

Love the ideas so far. However, I can't offer anything specific myself just yet. I'm still trying to get to Winterhold.

Investigating the reason why the Winterhold college survived the disaster and the rest of the city not and who was really behind it?
(As far as that is not revealed already, because I am not that far in the game yet to know.)

@Nowena:
You know about the carts-services in the outskirts of the mayor cities to take you there, for a few septims?

The more I play this game the more am I impressed. I am involved in two quests in Markarth and they are both interesting. 1) The Forsworn Conspiracy 2) The House of Horrors. Won't give any spoilers. Be sure to do them when you get to Markarth. E1 You get from the Jarl if you ask for work #2 from a guy you will keep bumping into if you offer to help. Take your time about accepting #2 as he will keep asking you for information.

I think modders will have a real challenge with this game. This is definitely not you ordinary Hack and Slash game.

Yep. I saw the carts when I first got to Whiterun, Kosh. I was going to try them out but then got involved in some really intriguing quests. (The one for the temple in Whiterun is not to be missed. That was a lot of fun.) So, since I earned quite a bit while raising my standing in Whiterun, I bought the horse and have been enjoying the scenery.

That is again my problem in Windhelm. It was on my way to Winterhold and I thought I'd stop in just long enough to sell the pelts and some excess bandit paraphenalia and accidently set off a major side quest (Blood on the Ice). So, I decided to finish that before I set out again. I have, but in the process, I found another that is really intriguing - The White Phial. Now, I feel I want to finish that one before I move on. Maybe I'll get a chance to use the carts after I get on down the road.

Nakia is right. This game is different and to me, a lot more fun. While I don't mind a little fight now and then, I really enjoy these quests that have more to them than Hack and Slash. I'm having a ball.

Oh. Gis has decided that he intends to do one of his special mods for the benefit of Winterhold when the CK comes out. He says it will be a cross between TEC and an adult Harry Potter. That sounds like a lot of fun, too.

Nowena, please keep us updated as to the mod. It does sound interesting and he does do a good job.

since you mentioned about the temple in white run, i would like to take this moment to point out something ive noticed....

White run is the city of Kynerith, and there is a sacred tree in the middle of the city.... what other city can you think of that had this same property?..... SUTCH! that was my idea for sutch, to have it devoted to kynerith and have the sacred tree in the center of the city... not saying that they took that idea from me, but it means that i was thinking on the same path as bethesda! which i am very proud of hehe just thinking that out there

any off that old rant and on to skyrim lol and @kosh, not i havnt found a reason either... although i speculate its a reason for why beth didn't finish winterhold, and instead of leaving it out like sutch, they gave us reasons, hints, and lore

ps, i have not gotten the chance to go to markarth yet or to the city that is rempresented by the deer... falkharth or something like that? im still learning all the names hahaha

Great Minds think alike./

hehe. People all over have noticed Beth borrowed many things from the best mods. No wonder we are enjoying Skyrim.

(Some of crafty bits has shown up, too, Nakia. And, bunches of things from CUO. I'm not surprised they've got a little Sutch in here, too.)