It's not just Ford though, it's pretty typical across a few manufacturers I have dealt with lately.
I know it sucks and they could do it better, but I always add a week onto their date and be patient, it just saves all the stress when it's not done, and you'd gotten your hopes up.
Everybody relax, you're getting a new car, don't stress it...
After you've spent 4 months with your car at Ford getting fixed with no progress, then come and talk to me about stress and cars...! Heh.
Tim