Complexity. I like how bethesda has eliminated some of it, for example, i love the new combat system by binding spells + weapons to hands, however, i feel that they tried to hard when it came to "dumbing down" the game. A certain degree was lost from morrowind to oblivion and I believe a certain degree to Skyrim. I would have liked to have seen more armor types, weapons, spell effects, skills, etc.

Don't worry, I'm not complaining, Skyrim is absolutely amazing, not trying to deny that.