Ok this isn't going to happen but I still think it would be pretty cool and there is no reason for it not to be a thing.

Staff and shield! All the animations in the game for destruction staff and restoration staff use their one hand only. The exception being when you block, you hold the staff with both hands...

You could make it where if you're wielding a staff and shield then maybe you don't get as much resource return or do quite as much damage vs if you leave your 2nd hand empty and wield the staff 2 handed.

I don't know why I happened to notice after all this time that literally 98% of the time my character is doing nothing with his left hand other than casting an occasional spell... but nothing to prevent him from holding a shield or even another weapon in that hand.

Imagine a staff and sword wielding Gandalf!

Like I said, probably most likely for sure not going to happen, like a lot of other things this game could use, but it's always nice to dream.

Edit:

While I'm on the subject of the staff I might as well mention that I would also love an idle walking animation holding the staff.... it's a staff, how many people in movies and such do you see with their staff strapped to their back? Theyre more used a status symbols and walking sticks than giving someone a reason to say it looks like you've got a stick up you butt....