I'd say its the removal of all thats superfluous. Perks are great, but they shouldn't be made to do everything. And I like the idea of one spell having multiple uses, but no spellmaking is just terrible. At this point it looks like diablo 2 had more depth for character growth, to me at least.
The graphics are fine, nothing special, but not terrible. Who plays TES for graphics anyway?
I'd have to say the weakness is going from a dedicated fanbase to mainstream. It will be far more successful than Morrowind or Daggerfall, but will it be better? Simplifying things to make it approachable to people who don't play RPG's, that doesn't sound like quality RPG design.
I tend to view Morrowind as transitional. It was a traditional RPG at it's core, but with a more action based interface and the two of them clashed horribly. That's why so many people didn't like the combat. When it came time for Oblivion, instead of adjusting the interface, they scrapped the RPG core of the combat system and went for Action, instead.
Thats an interesting perspective. How the combat was affected by the RPG mechanics, and a lot of people felt it was stupid. You make a very good point, I loved that, and yet I see it as a major complaint.
I hated that about Oblivion, and I know I won't like it in Skyrim. Action is great, but my stats should mean something. Thats why I play RPG's, for the character growth.