A mix of Morrowind's massive feel, and Oblivion's accessibility.
Bethesda seemed to realize some of these mistakes, at least in their claims that Skyrim would be approached from a "clean slate" sort of mentality. I can easily divide my feelings into two categories:
What I liked
The game feels huge, much the same way that Morrowind did. Simply from a geographical stand point, you are no longer in the "all roads lead to the Imperial City" that you spent the entirety of Oblivion trekking around in. The towns, of which there seem to be quite a few more, feel much farther apart, and quite distinctive from one another. Of course, being set in the frozen wastes of Skyrim, a lot of what you'll see is snow, mountains etc. Don't get me wrong, there are plenty of beautiful scenes, even if you're not wild about snow (personally I love it, and it looks awesome in this game), but I don't think you ever don't feel cold in this game.
Everything from the world, the water and the weater to the armor, the enemies, etc. looks simply breathtaking. Bethesda, for me, has consistently been the company that reopens my eyes to game worlds and graphical design, and this game has been no exception.
Crafting. Oh my goodness I have loved the crafting in this game, and I haven't even scraped the surface of it yet. Crafting is divided into two main areas (Enchanting is a seperate and familiar bag of tricks, so I don't feel the need to talk about it here): armor, and weapons.
You start off with a scanty few recipes and gain a ton as you go along. Materials are gathered from all sorts of logical places like killing wild animals for leather, raiding mines for ore, etc. There are tons and tons of ores to craft with - iron, steel, silver, gold, moonstone, orichalum (orcish), dwemer, glass, ebony, etc. - just to name the ones I can remember, but all animal hide seems to turn into plain old "leather". Nevertheless, whether you're wanting light or heavy armor, there is plenty to be had.
Crafting also ends up being very circular, synergistic, and passively helpful to you all in one fell swoop. Crafting items gains you crafting skill, selling those back to the vendor for loose change or possibly to fund further crafting boosts your speech (which is combined with mercantile in this game), and the recipes you gain from it not only allow you to build stronger items without having to go dungeon crawling to find them, it also lets you refine the items you already own with modest amounts of materials, making your armor and weapons more powerful.
Speaking of Speech, I like most of the skill changes they have made. For instance, Speech is now Combined with Mercantile, so I don't feel particularly compelled to either play the speech game with everyone I come across, or sell thousands of ingredients to a merchant, one at a time.
The new skill system is interesting, if not a little lean. You no longer pick a class at any point, though you can change your birth sign to increase the learning rate of either strength, stealth, or magic skills (which one of those does speech and crafting fall under I wonder...). Instead, you pretty much just do whatever you want, and every few skill gains you level up. With each level you get to pick a perk (*cough* talent point), though these immediately become limited by your character's focus, as they require certain hallmarks of skill to spend points into. For instance, the base skill for one handed weapons is a raw damage % modifier, which you can automatically invest in with the base skill. After that, however, you need increasingly larger amounts of skills to gain further ranks of this perk.
Weapon skills are now conveniently combined into simply "one handed" or "two handed", so you don't have to seperately grind blades, blunt, etc. Bows, of course, have a seperate "archery" tree.
These perks, undoubtedly like the WoW-ish talent points they are based off of, do make your character and choices feel much more relevant and potent. Even the lowest of these, like the damage modifier perks, can change your damage drastically.
Dual wielding is a very nice and intuitive invention. It's not that it hasn't been done before, it's just something that this game needed. Whether you're dual wielding blades like my rogue does, or using a blade and a shield, or possibly a blade and a magic spell, you gain an incredible amount of gameplay freedom and customization through this one, seemingly small, addition.
The lack of stat distribution isn't a huge deal to me. It was pretty self-explanatory in the last couple of games, and the choice between health, stamina, and magicka is pretty self explanatory in this one. You either want to stay alive longer, be able to cast more skills, or be able to swing your weapon more times before you get tired. The rest of the nuts and bolts of combat are still there, they're just packed into perks and items, and you don't have to fret over which words to click on while levelling any more. Some may be bothered by this, but as someone who really explored stats in Morrowind a LOT, I can say that this doesn't really detract from the game in my opinion.
I like that bounty's are local, and don't make the entire world hate you. Killing a guard in one town will only piss that town off, etc.
Stealth is also incredibly fun with the changes that have been made. Rather than simply being "hidden" or "detected", the game now makes enemy's have a scale of awareness that runs between those two states. An enemy can suspect your presence, and they will become alerted, at which point you have an opportunity to get to a better hiding place before they find you. This makes tighter situations and lower stealth levels both easier and fairer.
I'd also like to point out that the rewards for critical strikes have increased dramatically, making attacking from stealth much more fun and helpful. About halfway down the stealth perk tree you get the option to make these strikes more powerful, and you can find friendly modifiers in this regard on certain items (namely Dark Brotherhood armor). Right now my character does a whopping 30X damage with an attack from stealth while wielding a dagger.
Bethesda actually based this off a mod created for Oblivion that did the same thing. Sadly, a similar mod that made ranged damage very lethal, didn't seem to take as much effect on this game's development. Of course, my character at the moment isn't totally specialized in archery, but I haven't really seen the impact that the developer's promised bow-users yet. I suppose only time will tell.
As of right now I haven't been very far down the story line, but I'm impressed with how cohesively the world fits together nonetheless. In fact, I splintered off from the main story quests (not through lack of interest in them), and have spent hours and hours exploring the world and several of the guilds in it.
As I've stated before, the world just feels big. I felt like it didn't take me all that long to see most of what Oblivion had to offer, but in Skyrim I get the feeling that, as much as I've already seen, I haven't yet scratched the surface of what I'll be able to do in the game, and that's a huge point in their favor.
The world also doesn't feel like it's tracking your progress as it did in Oblivion. The level scaling has been, pardon the pun, scaled back quite a bit, just as they said it would be. Enemies do get more powerful as you go along, and on that note you can easily find enemies that will roll your face from the moment you enter the world (Giants and mammoths will one shot you for a long, long time), but it doesn't feel like a consistent and losing uphill battle like Oblivion did.
What I don't like
While everything I've already said was heart felt and genuine, there are some things I don't like about the game.
First of all, the technical issues that seem to haunt Bethesda have not been escaped with this game's release. For me Oblivion crashed constantly for years and years and still experiences occasional issues with this. Skyrim's release hasn't been nearly as bad for me, but still does crash between areas on occasion, and has a moderate chance of failing while Alt-Tabbing.
These are issues that this company needs to have a little time of self reflection on. I felt that Fallout: New Vegas as a far superior game to its predcessor, but got hit hard (and deservedly so) in reviews and by critics because of how buggy and poorly optimized it was. Fortunately neither FO:NV nor Skyrim were anywhere near the "buggy and unplayable mess" descriptions that crippled Age of Conan and other such games, but this is a trend that this company needs to part ways with, forever.
On a more positive note, the game runs very well performance-wise, with very seldom slow down.
Past the technical issues, the only things I've been really bothered by were very specific design choices. For instance, they've cut acrobatics, athletics and a few other skills that have been hallmarks of the series since Daggerfall, and yet have added the Pickpocketing skill back into the game (of note, as it has been absent since Daggerfall...), a skill that could easily have been combined with Sneak, and probably should have been.
The marriage thing. I'm not opposed to this at all, but... when Bethesda decided to go the whole "marry whoever you want, regardless of race or sex thing" it definitely through a wrench in the works. For instance, I helped a girl character through some troubles, then had the option to marry her if I wanted to. Ok, cool. Then, I got challenged to a fist fight by a random dude on the street and won, after which he was also marriage-able. Wtf? Yeah, so when you go with the whole "everyone in Tamriel can swing both ways" thing, it can get pretty weird and strange, and pretty quickly. On the other hand, you can just not by the Amulet of Mara, which you have to be wearing in order for the marriage dialogue options to appear in the first place, and avoid the awkward situations altogether. On a further note, It appears that only non-important NPC's are available for getting hitched, and that's a little depressing. I'd much rather be tied to a high ranking member of my guild than some random chick of the street. After all, whoever you marry can be used as a fighting companion, so the hot assassin chick dual-wielding the awesome daggers seems like a much better wife than the street grocer who would probably throw cabbage at them. Just saying.
Windows. Where the hell did they go? To say it clearly: there's basically no character screen any more. I had to search really hard just to find my active skill bonuses. The whole "wheel" window thing to me is far too simple for a game that started out as deep and complicated as Daggerfall was and, yes, I'll say it: "consolized". More than the lack of stat distribution or anything else, this reeks of "consolization". Fortunately, it didn't burn me because I enjoy the rest of the game so much. However, I can see some diehard fans of the game and of PC's being put of by this. Doesn't help that mouse support is beyond poor, and there are quite a few menu actions that CANNOT be done with a mouse. Bad move, developers.
Still not a fan of stolen items being flagged as stolen. It helps that bounties are strictly local, but why would a merchant in town A care (or even know for that matter) that I'm trying to sell him a sword I stole in town B? Especially if the guards in town A don't care that I killed a guard in town B while I was stealing that sword? Doesn't even make any sense, considering that I could have killed a guard and taken his stuff, and it not be considered stolen. Unfortunately, I can tell you exactly why they did this, again, and I have to say that I'm thoroughly unimpressed by the reasoning. Here it is: they're in love with their idea of fences. How do I know that? Two reasons: first of all, they still have the fences in the thieves guild. Secondly, they even added a perk in the Speech (Mercantile) perk line that allows you to sell stolen items to any shop you've invested in. Yeah... that's loving an idea way more than it's worth, especially considering that the vast majority of your gaming community didn't like it in Oblivion either.
Overall this game is great. I'm enjoying it a lot more than I did Oblivion. From the awesome and convincing weather effects to the large crafting system that is, in a word "fun", this game is well thought out, and well made.
Unfortunately, I can see a lot of die hard fans that were attached to Morrowind and hated Oblivion getting put off by the simplification of some of the elements that I mentioned, and still others being turned off by the technical issues, but I think that overall, this was a major step in the right direction for the series.