Uninformative character/stats screens. There is a lot of information that goes on behind the scenes, which the character screen does not relate in Diablo 2, but which is very important to know, especially in the later difficulties. A good example would be magic find. Having to manually calculate your magic find % is quite unneccessary. If we assume that magic find may not be in D3, I am sure there will be other stats and information beyond the basic things like health, armour class and damage, that we will want relayed to us.