“Silverlight is a cross-browser, cross-platform plug-in for delivering the next generation of media experiences and rich interactive applications (RIAs) for the Web.” – Microsoft
Now as far as i heard the SL can stream Video (probably wmv) using only IIS ( internet information server ) then oh uh its the new Gen indeed , would that effect Flash video files (FLV) ? or Adobe got its own surprise , you know Adobe is full of it now days 🙂

http://silverlight.net/