I don't really feel the need for more than six ability scores, but I do have a serious urge to mess around with a few of the existing ability scores.
Wisdom, as it stands now, is an extremely poorly-defined score. Apparently, it means sensory acuity, willpower, and . . . receptiveness to higher powers? Is that what Clerics use it for? I don't even know. Anyway, none of these things are very strongly related, and none of them are really "wisdom", anyway.
Charisma is also pretty weird. Apparently, Charisma is also willpower (sort of), in addition to being social presence, and possibly physical attractiveness, too.
I'd like to revise those two scores into more clearly-defined Perception and Willpower (or maybe Ego?) scores. I can actually kind of buy perception--in a mental receptiveness and sensitivity sense--being useful for Clerics and other divine types. Obviously, it would be used for skills like Sense Motive, Spot, Listen, and also Search, and would have nothing to do with Will saves. It could, however, be associated with Reflex saves and Initiative checks (which, as long as we're revising stuff, should probably be the same thing, as in Conan d20). I also kinda dig the idea of using Perception for projectile attacks or, at the very least, magical ray attack rolls. (I know I'm robbing Dexterity, here, but I'd also like to use Dex for melee attack rolls, and possibly some of those Str-based athletic skills.)
Willpower/Ego/whatever could keep Charisma's social skills, since it would quite logically include a sort of "presence" factor, and would obviously take over Will saves. And it'd make all the sense in the world for Sorcerers and Use Magic Device checks, of course.
As for the "appearance" aspect of Charisma, I feel pretty comfortable not using a stat for physical attractiveness. It's an impossible enough thing to quantify in the real world; it'd be completely absurd to even try it in a setting with three dozen intelligent species running around.