Set items you want to hotkey to your favorites in the inventory (default "F" key) then close the menu and open the Favorites menu (default "Q" key). Once there, highlight the weapon, armor, or spell and press the corresponding number key that you want to hotkey from 0-8, and there you have it. Limited? yes. Better than opening an inventory or magic screen to witch gear (even the highly convenient favorites)? Absolutely.
So far my only problem is that I can't get a silver sword to stay hotkeyed on the 1 key. Don't know why, but every few minutes, it drops the hotkey, but only when I have it set as silver sword.