We've covered one of these before, but i felt they could probably warrent a little more exposure.
Although tedious to start with, these videos and their demos are absolutely staggering. Especially interesting was the graphics in the Manufacturing video, with vectors objects looking like something produced by Stardocks! Videos like this really do make you look forward to it's release.
"How can Longhorn's new platform technologies help you deliver solutions in your particular industry? Watch video demonstrations as Carter Maslan from Microsoft's Platform Strategy and Partner Group highlights some of the work being done in various industries to create a new class of connected applications. See how the Longhorn Fundamentals, Avalon, WinFS, and Indigo pillars combine to help you coordinate end-to-end business processes across organizations and systems."
Definitely worth a look.