Thanks for the welcome DrDRum! I was starting to think these forums didn't want me =(
I really like the ideas you offered.. I"m going to start working towards running 8 enchantresses, and taking out the black. You're right about the tutors and the Yawgmoth's Bargain (I never really thought about how little I actually use it in games until you mentioned it). I personally think Aura shards is a great card for mirror matchups, and its a good removal without having to give up cards for Disenchant, etc.
I've had some feedback that this deck is a bit short on creatures... what other sorts of creatures would you suggest I add?