One problem I've always had with MMPORG economies is the way game mechanics keeps pumping more and more coin into circulation from mob drops. It can lead to horrendous inflation that makes it tough on the new player to compete for gear against the twinked characters of established players. My suggestion would be that the currency in game would be the mana/chi collected from soul stones that you'd use during especailly tough fights to super charge enchanted weapons or instantly restore mana for spell caster types. Since the soul stone energy would be consumed you wouldn't have ultimately meaningless hordes of gold piling up and bloating the economy.

This actually leads to a good point - they need a new currency. The Septim can't be used like in other TES games, because the Septim bloodline doesn't exist in the time period that TES:O takes place. I don't know if using souls is a good idea, but it's an interesting point nonetheless.