Putting points into Intelligence for a Warrior doesn't do a lot. The extra Mana can be useful, but later on you could find good enough equipment to bring your max mana high enough that you'd need a lot of time to go through it all.
Basically, the main reason to put points in Intelligence in <img src="/ubbthreads/images/graemlins/div.gif" alt="" /> (even for a Mage) is to give you more mana early in the game, as later on you can get FAR more mana from nice magic weapons/armor, and by putting quality Charms in your equipment. Note that putting Charms in your equipment requires the skill from the Warrior screen AND having equipment that says it has Charm Quality.
