We all know that in Oblivion, and I'm assuming in Morrowind as well even though I never played it, you could just spam that conjuration / restoration / alteration / mysticism / illusion spell over and over until they are at level 100. This is a terrible thing! This is basically just cheating. Change it so that each of those skills can only level up when it actually does something. So for example, restoration wouldn't level up until it's healed X amount of health, conjuration wouldn't level up until your conjured creatures have done X amount of damage, etc etc.
I don't know if this has already been mentioned before or even covered, hopefully it has and it will be changed.
So far, Todd has confirmed in the interview with Norwegian magazine Gamer.no that in Skyrim we will no longer be able to "cast Unlock on a door hundreds of times to level up Alteration," and that the dev team has eliminated most of the meaningless repetitive leveling activities from the game.
Hopefully this includes spells from the restoration and other schools as well.
I don't want to spend hours of precious game time in Skyrim casting an Apprentice level healing spell on myself over and over in order to unlock the Journeyman healing spell that I just bought, for example.