also random traveling merchants and hunters and people that gather resources you find randomly in the wilds selling the junk they gathered

As far as future expansions go I have just one word:

Morrowind

That is all :P

It seems like the story is pretty straight forward at this point with a pyramid of baddies with Molag Bal at the top. It would be fun to see some other big faction of baddies (or really antagonists. They could even be not evil just opposed to the PC's) that take advantage of the chaos to enter the fray. That could provide all sorts of new quest, dungeon, and pvp zone content and it would break up the monotony of "Oh, it's the Bloodthorns/Mannimarco/Molag Bal here to be bad again."

And, of course, more parts of the map being opened up like @Enigma1985 brought up.

I'd also like to see some of the unique daedric items (wabbajack, mace of molag bal, etc..) becoming something to compete over in PVP, so that there's something special to compete over other than the one big spot on the throne. Maybe you can only hold the items for a time unless you fulfill quest demands for the daedric prince tied to the weapon and if you fail to do so the item is lost again and the first person to stumble upon the daedric shrine is offered a quest to get the item. Of course, this would make that player a target and people who defeat him get the daedric item (and the requirements to do the quests along with it).

Obviously I'd like to see some fixes to the interface. The biggest thing that would make me happy and would save me some time is being able to toggle between my inventory, the bank, the build bank, and the guild store without exiting out and talking to the NPC banker again.

I also would like to something along the lines of heirlooms or some sort of power leveling for characters on the faction. I can see it getting tedious for players trying to level their third alt in the same faction because its basically the same content for the third time. Shouldn't force players into a 100+ hour grind just to get an alt.