Now, I haven't been keeping up with these boards too much, so this might be out here.
Basically, my playtest group realized that it was absolutely retarded to have the DC of Specialist and Domain Spell-Likes be Cha-based. It makes the spells that are supposed to be the Clr or Wiz's signature abilities in fact weaker than general spells. Now, we realized that it makes sense that force of personality would factor into this, since it more of an innate power. Therefore, we suggested the following formula:
DC = 10 + spell level + primary casting ability bonus + Cha
This makes these innate abilities really hard to resist, and since there's but a few the Wiz or Clr can cast each day, the high DCs won't break the game. Also, if Sors or Brds get abilities like these (possible, but we think unlikely), then these basic powers of theirs would be exceptionally hard to resist, which kind of fits.