What if... instead of more armour slots, you could have layers of armour on you. I mean it would keep you warm having a wool west underneath that chainmail. Just look at http://www.uesp.net/wiki/File:Nord_official.jpg picture. It looks like he could use some more clothing or armour? Perhaps a fur coat covered in steel plates. Dunno. It would be a cool asset though. What do you think?
I definitely like the idea of layers of clothing and armor. It worked really nicely in Morrowind. I liked being able to wear a shirt under my platemail and a robe over that.
I'd like a few weapons layers too. Ya know, like your favorite weapons will show up on your body if you want em to. Claymore on you back, two shortswords at your sides...stuff like that would be cool too.