I thought oblivion had quite good armour,it wasn't a bad selection really.
We had: Fur,leather,chainmail,mithril,elven,and glass,light armours. Also amber if you had SI.
Heavy we had: Iron,steel,dwarven,orcish,ebony,and daedric. On top of that we had guards armour,blackwood armour ( ok same as steel,but black ),and madness from SI.
I would say thats quite a few.
In skyrim i believe we'll have more.I 'm going to guess what i think will appear in skyrim.
Light armour: Fur ( different types ) like: wolf skin,bear skin,mammoth skin,maybe even sabre cat skin.
Leather ( we may have different types here,not sure ),elven,glass ( glass should have different colours ) stahlrim ( ice armour ),dreugh armour.
Heavy: Iron,steel,dwarven,orcish,nordic,ebony,daedric,dreugh ( could be classed as heavy,if in ),dragon scale,dragon bone,possibly silver armour,some sort of imperial armour, templer etc.
I doubt we will see amber and madness in skyrim,would love to see amber though,as this is a resin from trees,so should be in ,in my book.
We may have others too,as we or i rather,don't know what other materials exist in skyrim,so we could have even more,with crafting/smithing etc.
Thats my opinion of what armours may appear in skyrim,i may be wrong,but i'm willing to bet there will be more than oblivion.