If that thing about the little ball telling the orientation of the unit to adjust the circle-of-lights is true, then that is an awesome idea by MS. I'm sure its not the first time that idea has been used, but its a first for consoles, and a good one considering the lights tell which controller is in use.
As for date stamps, I think the Pepsi "One Every Ten Minutes" Xbox360s were made before the ones that shipped on the 22nd. My Xbox360 says October 23rd 2005, and I got mine at Costco at 9am on the 22nd. We'll have to see what other Nov 22nd buyers and Pepsi winners say about their date stamps.