Great analysis over at the Jovial Priest (here: http://jovialpriest.blogspot.com/2010/12/no-dump-stats-every-ability-score.html) about making all stats important, especially regarding INT and WIS, which usually become dump stats for everyone but magic users and clerics.
His brilliant concepts:
INT score is the only thing which provides an XP bonus, for all classes. Makes sense to me, as the smart learn faster. His rule:
Only intelligence gives XP bonuses, not prime requisites.
3-5 (-20% earned experience)
6-8 (-10% earned experience)
9-12 (no bonus)
13-15 (+5% earned experience)
16 + (+10% earned experience)
WIS score provides savings throw bonuses against all magical attacks, not just those affecting the mind. This is justified because WIS encompasses intuition and judgement, which would be critical components of overcoming magical attacks, even purely physical ones. Again, makes perfect sense to me.
The "combat effect" of high WIS is like a character's "spidey sense", providing him with vague foreboding of danger, putting him on the alert, helping him make the right choices in those crucial split seconds when a deadly attack is being launched.
After all, let's say you are being targeted with a death ray... Your physical speed will not help you here, the ray is too fast. What matters is, what were you doing BEFORE the ray was launched??? Were you already ducking for cover, pulling your shield up, etc?
That is the bonus effect of high WIS: quantifying the benefit of things you did before the attack was launched, subtle actions which your intuition and judgement lead you to take, as well as the positive effect of your willpower in overcoming the ill effects as you are being effected.
With these slight tweaks, INT and WIS become potentially useful to EVERY class, and character creation becomes a much more interesting and thoughtful event.