Max carry weight:
Strength x 3
Things should also weight more, and heavy armor should not weight 0 once you are a master in it.
Repair hammers should weight 3 or 4 each, i'm serious. This would make the less pro in the skill not able to repair as much.
Weapons should also weight slightly more, because it is too easy in Oblivion to carry 5 different weapons and simply switch as the situation demands for it.
One thing i've always wanted is to see, everything I carry on my character in third person mode. That would be so cool, to see the bow and arrows in your back, repair hammer in your belt, a small purse with your money in, poison bottles in your belt, sword in your hand, dagger in your boots..
Maybe a mod?