Skyrim has taken massive leaps forward in some areas and massive leaps back in others. But I'm going to be uncharacteristically optimistic and say that most of what is good about Skyrim would have been hard to mod and most of what is bad should be easier to mod. For example, in comparison to Oblivion and Morrowind, the spell effects look much better and magic duals feel more visceral with the ability to ward and continue channelling a spell until your run out of magicka. But that came at the cost of a decreased number of spells, no spellmaking, and removing a school of magic. But adding in dozens of new (but balanced) spells is a task most modders are better suited for than creating new animations. Another example: we have pretty decent animations for smelting, forging etc (which would have been hard to mod), but we're lacking a reason to eat, the ability to pay for enchanting or smithing to be done by NPCs on your behalf. But most modders would be better able to create a hunger/cooking system than they would the animations for them. There's also a lot more personality in each dungeon, and the world looks great, but the dungeons and night are far too bright. Bur, playing with lighting values should be a lot easier than creating new models or even textures. I imagine in a year or so, somebody new to Skyrim will be enjoying the game immensely with a host of great mods that add to the realism, balance and fun. In much the same way I enjoyed FNV when I played it earlier this year due to great mods like Project Nevada.