It would be really cool if the current skyrim "hands" based equipped magic and melee function were somewhat combined.
This way you could equip both a weapon and magic into each hand but the material and type of weapon (or shield) would modify the effect if both are equipped at the same time.
thus is you had an iron shield and a heal spell equipped using the heal will give you a half strength heal and a shield spell effect, whereas with no shield equipped would just be the heal spell. Different material shields would give a different effect.
since there is a sizable number of materials available, weapon choices and a number of spells, this would add real depth to the combat since there would be a lot more choices.
do you equip the iron shield and a heal spell that gives extra shielding when you raise your shield, or do you go with the fire magic which makes a flaming shield, or go with no shield at all and just wield magic in that hand. So many ways to work it and so many possible effects.