My next thought, of course, was about staves. They are the traditional mage weapon, but have only played the role of charged spell wand in Oblivion. Do we know if Staves are even in the game?
If they are, my suggestion is thus; wielding a magic staff should count as having both your hands free for the purposes of casting spells! That would actually make Mages use them, and give them a nominal weapon whilst letting them focus on magic. Ideally, any spell they cast when equipped so would fly off the staff itself.
Its prolly late for suggestions, but maybe it already works this way, and if not, perhaps thats a feature they can consider for the first expansion Thoughts?