I had contributed two part article for Developer.com about Longhorn long time back when it was in early alpha stages. I remember the day in which I received around 12 white CD's containing Longhorn.
Longhorn Coming Attractions - Part 1
Longhorn Coming Attractions - Part 2
I've posted the links for the benefit of the community. I look forward to write articles like this after the receipt of Windows Vista next year which is just 5 hours away. I'm expecting it shortly.