Hmmm... So I'm considering a simplified version that combines my ideas with some of Light's:

The Aetherscape is a giant energy bubble around the Mortal Planes and is split into four quadrants - the Elemental Planes of Air, Earth, Water, and Fire - and in the center between them is the Infernal Abyss, where all dark magic is pulled from. Beyond the outer edges of the bubble is the Cosmic Void, where magic pertaining to space, time, and gravity is pulled from. Any character can learn to harness any kind of magic with the right training, but they are born with a natural affinity to one of the Elemental Planes. 

The actual classes at the Academy focus on different methods to use the magic. So, for instance, the Professor in Evocation class would teach students how to evoke blasts and such of their attuned element, the Enchantment Professor would teach them how to enchant items, the Runology Professor would teach them the various runes of the Ancient Tongue, etc. 

What does everyone think?