As far as I can tell, Int makes no diff to your damage, though it's extremely difficult to accurately come to any conclusions, as each mob seems to have it's own variables. Fighting in RoV, I can use the exact same spells on the same mob of same lvl and one might seem to take consistantly less damage than the other over hte course of the fight. Maybe it has better resists, or maybe my luck wasn't as good. If intel makes a dif that is small, it would be hard to figure that out due to the very large range of damage possible from any given spell. Your low might be 60% the damage of your high on the same mob in the same conditions. How do you calculate for what might amount to a 2-3% affect? By the time you'd popped enough nukes in a controlled test, you'd have lvl'd.
Int does definitely increase your power, and wis does at least seem to decrease the chance of getting resisted, so I'd consider those to be the 2 most important stats for a wiz. Not to say other stats are useless, but as you are a caster first, the stats that impact your DPS most directly would be the ones I'd work on increasing the most. Stam and Agil are nice if you solo all the time and find yourself in the roll of tank as well.
