I have the AA Platinum Mastercard as well, and I will soon call and attempt to cancel to see what they offer. If they waive the fee, I'll keep it; otherwise I'll just eventually tell them to downgrade me to bronze. I'll post the results of what they offer.
I have entirely too many cards with an annual fee and do not use this one enough to justify the $85 fee. I figure with the bronze I can still add a few AA miles to my account each month that I don't fly...even with the lousy 2:1 earning ratio. Plus, I have the SPG Amex if I want to txfr miles, and I pay for the Amex Platinum, so it's time to cut back on the other annual fee cards I don't use.