Okay, there IS a work-around to the delay in computeredness, if one is politely persistent.
I called FedEx, and since the ground shipment hadn't gone out yet, they were able to pull it so that I could come by with an overnight-shipping label. I called Apple to let them know that I would like to return the laptop via overnight delivery so as to minimize the amount of time I was without a computer, and suddenly, I find that I can give them the tracking number for the return shipping and as soon as they confirm that the original laptop is in fact en route back to them, they will go ahead and have my new laptop sent out.
So, a happy resolution in the end.