Hello...
I don't know if this is already integrated in skyrim...if so, it's way too subtle to make any difference...
When I decide to develop a "light" character (a ranger, an hunter, an assassin and so on) and I give up with all that shining heavy weapons and armors, I give up with mass damage too, and I would like to be rewarded with a noticeable increase in speed and agility... I should be able to circumvent any enemy equipped with heavy armors and weapons and stab them in the a$$ 4 times before they can turn their backs.... I should be able to run away and lose who's chasing me.... etc ... I do not expect to run faster than a deer.... but rabbits shouldn't humiliate me that way !
So, is there a way to make "agility" really valuable during combat? you know, the difference between heavy and light combat shouldn't be limited to the amount of raw damage...