So my brother has game informer magazine because he works at Gamestop. The recent issue had Skyrim as it's coverstory. Screenshots were inside. Here's what I can tell off hand after reading a bit and examining the screenshots, assuming they were shots of gameplay and not cutscenes.
1. Being an assassin will mean something.
The elder scrolls series annoyed me when you were supposedly an assassin, and all it meant was that you used light weapons and light armor. One screenshot shows a very up close and personal assassin's creed-esque stab to the gut kill shot.
2. Oblivion 2.
Here again we see a sword in the right hand, and magic spells being used in the left. Expect the same lack of class distinction since you'll more than likely be able to be good at everything.
3. Digging out of the Uncanny Valley.
One of the major points of the screenshots was that the character faces are vastly improved over what we had seen before in Fallout 3/New Vegas, and Oblivion. While New Vegas was getting there with better faces and a variety of voice actors, Bethedsa promises to take this further in Skyrim.
4. Variety in scenery.
There is far more over land variety displayed. Certainly not a completely frozen tundra, to say the least. Various kinds of trees, etc will do much to make things seem less generic than Oblivion. Still, it doesn't feel quite as alien as I'd like. Morrowind was perfectly alien and familiar, with plenty unique scenery to satisfy most.
5. Fallout 4: The Elder Scrolls
Bethedsa implies that they're borrowing a great deal from Fallout 3 and New Vegas for this game, including the perks system that Fallout 3 used. While Oblivion had perks, they were not customizable, something unlocked as skills grew to 50 points, 75 points, and 100 points. And on the whole, they were pretty boring.
Everything I read and saw implies that Skyrim will appeal to everyone who liked Oblivion, and Fallout 3 even more.
Moving on, as for the debate about whether or not Nirn is a Daedric realm. Sure, why not? There is no implied real difference between Daedra and Aedra. After all, Aedra is simply the elvish word for Ancestor, and Daedra simply means, Not Ancestor. Of course Nirn may have been created by the Aedra, but that doesn't mean that Daedra and Aedra themselves aren't more or less the same.
Of course, this means Daedric realm is a poor choice of word. A better way to put it would be, functionally the same as a Daedric Realm.
After all, you do visit the Realm of Sheogorath, and you do find that the only real difference between it and Nirn is that you're the only sane person inside it. Except for Sheogorath's butler.