Interesting post -- the similarity in each of the curves (prior to CD->digital, anyway) is totally fascinating. With more data on paid downloads becoming available, there should be some fun exploration possible there before too long.
As I guess is clear, it seems to me like these ideas should have been pretty obvious to Microsoft (though I happily accept the compliment regarding my insight and creativity).
It just seems incredibly strange that it occurred to no one at Microsoft that the wifi sharing that's at the heart of the launch campaign only works when you've got more than one Zune in the same place.
Even if sales had started and stayed huge, it would take a while for Zunes to become a common sight. If "the social" was the heart of the campaign, why wasn't anyone at MS asking "how can we ensure that everyone who buys a Zune experiences 'the social' within a [week,day,hour,whatever] of purchase?"