Allow me to throw my two cents in here.
Ok, fine. Mental stats = Uber Spellcaster, where Physical stats= equal balance.
Then why is it Half-orcs get -2 to Int AND Charisma, for a +2 to Str? Apparently, Physical stats are more important then mental (Considering how the books state how to balance things in this reguard). Everyone's willing to make a Halforc and cut down on his personal appeal and intelligence. Sure! I can hit stuff! But add an ability to get better stuff on a spellcaster class, and folk go bonkers.
Why not give them a hurt in something like a -2 to Con, or -2 to Dex? Those are important to wizards. Thus, it's an exchange. You get less HPs, or easier to hit.
Then why not a Mental Stat for a Mental stat? I miss the old +2 Int, -2 Wis Gnomes used to get.