I'm surprised no one has mentioned this here.
AmEx sent me a later today stating that my cashback is being reduced. From October 1st this year, they'll be paying out (annually, again):
0.5% cashback if your total annual spend is 2,001
They've also decided to change various other aspects of the Blue Card service. For example, money back cannot be earned if it totals < 5 over a year. Also, the standard interest rate for balance transfers (after initial six months of having the account) changes from 9.9% to 12.9%.
So, is it time to get the American Express Platinum Credit Card? I've had my Blue card for just over three months now and have so far spent just under
4,000.