A while back I apped for both a Delta Skymiles and an AMEX Green Charge. I have received the charge card, but not the Delta. I signed up for online for my Green and looked at the banner above advertising the AMEX Blue Cash's features.
I called their customer service. Initially, and immediately, he said "we're sorry, we cannot process the change at this time." I persisted, he put me on hold, and they will process the card change on 1/9/08.
Exciting stuff, it really does work.