In 2000 I saw C# and knew at once that (wanted to set aside c++ and write exclusively in, and about, .net.
Today I saw Silverlight (WPF/E) and had a similar feeling.I believe that, in 1-2 years:
There will be few reasons to develop in WPF
There will be few (no?) reasons to develop in Asp .NET-AJAX
Silverlight represents the ability to build incredibly rich, interactive, media intensive applications that are delivered over the web, through standard browsers, and across platforms