After spending a while with Skyrim I guess I have more coherent thoughts on the gameplay itself:
It's Elder Scrolls. That much is apparent. Turn up the combat to Master and it's still not amazingly challenging on a regular basis, but at least you don't kill every enemy in 2 seconds. Mana and health regen almost entirely ruin the point of bringing all those potions and food around. Spells feel much more simplified and limited in scope, but dual-wielding partially makes up for it... and let's face it, I don't really need Fire Spell 1 and Fire Spell 2, if they basically do the exact same thing but one does more damage. Combat is enjoyable but nothing really new - it gets the job done but this is not really a game about fighting anyway (unlike say, Divinity II) so I am willing to forgive the fact that I can get better combat elsewhere.
As for world design, I like. There are still stupid things that cut into realism and believability, like huge bandit camps out in the middle of nowhere with no obvious supply lines, the game world is a good size but the wilderness doesn't feel as expansive and endless as I'd like (more roads and obvious paths to follow), towns are nice but as with other Elder Scrolls kind of feel sterile - people do jobs and stuff, but I don't really get the sense they're bustling with activity. Needs more crowds, more people, more noise. The art direction and landscaping is tremendous and honestly probably the most impressive I've seen in any game, ever, and the dynamic weather and changing between climates really is extremely well done. Overall it's a huge step up from Fallout 3 and a little better than Oblivion, but there are just too many immersion-breakers that make you go "wait, what?"
Quest design, surprisingly, seems to be a strength of the game - not so much in terms of the quests themselves but in terms of choices and consequences. It feels like New Vegas in the sense that doing quests for NPCs and factions seems to lead to newer and better things, and there are times where NPCs will respond to you differently depending on your play-style. However, due to the lack of reputation pop-ups everywhere, the system feels much more natural to me. There are also random encounters, unmarked locations to find, etc. and generally it feels like there's always somewhere you can go and something to do, something woefully lacking in Oblivion despite its sheer size.
Cooking, smithing, alchemy and so on are all welcome. They don't seem particularly useful unless you're able to get much better equipment later on (more unique crafting-only stuff would help), and it'd be nice if there were schematics and whatnot required for some things, but alchemy at least requires experimentation. As with all crafting systems though, ultimately you're basically just wading through menus, which is never really fun.
Of course I've only played a few hours so I don't want to make too many assumptions, but it seems like Skyrim is somewhere in between Oblivion and Morrowind in terms of quality, leaning towards Morrowind. The simplified character system just plain sucks, the UI is awful, the lack of real persuasion options and whatnot is a bit disappointing (at least so far), and combat is too easy to be tactically or reflexively engaging, but like all other Bethesda games it claws back a lot of favour simply due to how much there is to do, how big and interesting the world is, etc., and in that respect Skyrim is definitely a big improvement. It's a shitty RPG, still, but as far as sandboxes go it is really well done.