The PDC keynote, featuring Bill Gates, Jim Allchin, Don Box, Chris Anderson and, on video, John Scully, Marc Andreesen, Bill Clinton, Warren Buffet, Sean Combs (P. Diddy) and lot of other folks ... was easiest the best, most substantial, longest and fun keynote I've ever seen. And I've seen very many.
Longhorn, the Aero shell, the Avalon programming model, WinFS and Indigo rock already and they are going to get better and better as time progresses.
Hey, Linux Penguins, here's the new thing to clone. Good luck.