Since it looks like we will be getting an upgrade to our charm spell in OoW, I have been concidering buying all the AA +CHA abilities. However, I have never seen a reliable guide explaining how much CHA helps charming. Does anyone know the answer to this or a good place for me to go look?

It's been tested thoroughly. Charisma doesn't help druids at all with charming. Don't spend you AA on it.

the only classes Cha helps for charming is Bards and Enchanters.

wow, thanks. That will save me some wasted AA