So I've compiled a rough list of things to give people some perspective as to how Skyrim actually holds close ties with one of the more in depth RPGs of the series. This is by no means a full or final list, and I may revise it as I go.
Radiant Story: Arguably the closest similarity to the randomized elements in the quest generator for Daggerfall, but pushed a step further. On top of keeping things varied and interesting, it also promotes exploration and caters to providing different experiences for different playstyles.
Fast Travel: Skyrim has two options of travel. A paid service (carriage) which is akin to Silt Striders, but also the means of Mage's Guild Teleportation (Daggerfall) and a map function that calculates the trip, and the funds "necessary" in a roleplaying sense (EG inns, food, etc). While one could say this is a blend of two different, as Daggerfall had both options it again is its closest cousin.
Difficulty: Gone are the slider bars of Morrowind and Oblivion. Instead we are blessed with the concept of difficulty settings. What they entirely entail seems to vary, but goes well beyond the means of simply nerfing your damage output while increasing the enemies'. Whether or not the difficulty setting like the reflex setting in Daggerfall will reward you with faster leveling is beyond me. It's something that we will have to wait and see.
Character Customization: Again, while not quite as in depth as Daggerfall's generation system, we again see a return of one of its systems. Arguably two similar characters in Morrowind and Oblivion have very little to individualize oneself, while Daggerfall and Skyrim boast a way to broaden the gap between each playthrough, and branch us out in multiple ways of progressing through the game while keeping it fresh and engaging. However, while Daggerfall maintains more depth, the Skyrim system of perks is much more progression based (and thus more approachable by beginners or players that have yet to set foot into Skyrim, as particular choices in disadvantages in Daggerfall can be particularly handicapping).
Dungeons: Personally the perfect blend between the hand crafted dungeons of Morrowind, and the expansive size of Daggerfall's with the return of traps and puzzles. An additional bonus is the concept of level locking over Oblivion's level scaling, making difficult dungeons stay difficult until approaching them later on, again rewarding players for actually progressing with the game.
Alchemy: Blending the various flora and other substances found in the game world now is more appropriate to appropriate knowledge or trial and error, instead of simply being restricted by ones current list of ingredients and alchemical skill. While the systems in Morrowind and Oblivion were different, they were by no means a bad system. It does beg the question though why the same ingredients without the aids of tools and refining can suddenly "gain" more effects.
Attributes: This is a real can of worms in particular. While a lot of them have simply been merged into other groups, and simplified to fewer categories and less tangible numerical increases, how attributes and skills are tied into progression are again most similar to Daggerfall. Morrowind and Oblivion had systems that tethered your progression to your skill use, either horribly restricting your early game potential due to not using specific skills (EG fighters avoiding endurance based skills to not have a measly chunk of HP with races not pertaining to Orcs and Redguards) where creatures are lethal (especially if RNG looks down on you unfavourably) like in Morrowind, or your late game potential where things scale (EG not maximizing your potential increases of attributes, allowing the creatures that scaled to become considerably better than you over time).
I'm sure I'll be sieged with an onslaught of "then why is 'x' not in the game" or "but this very minor feature that only caters to one type of playstyle and only in limited used/areas isn't in so it's less deep", though hopefully you have will gained a little bit more perspective on this, and why I as an avid fan of PnP, RPG mechanics, and the TES series, believe Skyrim will potentially be one of the best games in the series.