Rob Bagby , MSDN Developer Evangelist, will present Silverlight  1.0 on Wednesday, 15th August at 11:00 AM Pacific Time (US & Canada).
Register online  at Microsoft Events; the level is 200.
There is another Silverlight Overview MSDN Webcast with level 100  available from Rob:
In this webcast, we provide an overview of Microsoft Silverlight, including a discussion of Silverlight XAML, Microsoft Expression Blend 2, animations, media, and programmability. We also discuss features included in versions 1.0 and 1.1 of Silverlight. We encourage you to attend this session as a jumping off point for further webcasts on Silverlight.