I have to say that despite the bad press Silverlight is getting at Wikipedia, I was pretty impressed using it in the NBC Olympics site. Four live feeds at once? Yes please. This is what digital television was supposed to bring us, but never did. More important, fast forward, rewind and skip were stunningly responsive, which is more than I can say for Flash-based video. Finally, over my decent but not world-class DSL connection, video quality was fantastic, even at full-screen.
Yeah, Silverlight uses proprietary software and eschews open standards. Like Facebook's closed platform and data policies, this bothers me. But like Facebook, Silverlight is simply ahead of the competition. Until the alternatives catch up, you can't blame consumers for sticking to the closed (but superior) platforms.