In this concise but not-to-miss article, Rockford Lhotka (one of the brighter stars in the pantehon of technical writers) provides a brilliant summary of Silverlight's promise.
My only objection? Like so many others, Rocky hangs too much on Silverlight 1.1 and seems to miss that the revolution has already begun; 1.0 is here; Silverlight is live, and the time to begin is now.
Stay tuned; I plan a webcast very soon with the title: Silverlight: What Are You Waiting For?
In the mean time, don't miss Lhotka's article.