For the Next Major Update...
Magic Resistance! There NEEDS to be a magic resistance stat. It would balance the game out AND fix a whole lot of problems with the magic system being underpowered. Now, instead of having enemies like trolls and spiders (enemies strong in physical attacking) take pitiful damage from high-level spells, you could have magic instead ignore armor and focus on magic resistance. Magic resistance could be derived from INT or WIS, or you could get bonuses to it from enchanted armor and weapons even.