Silverlight 2 Beta2 includes some significant Media related feature work:

Adaptive Streaming

Beta2 adds support for "adaptive streaming" - which enables you to encode media at multiple bit-rates and then have a Silverlight application dynamically switch between them depending on the network and CPU conditions.

This enables much richer end-user media experiences - since it makes it possible for content providers to provide both lower-end and higher-end bit rate versions of a video, and then have Silverlight choose the optimal one to use based on an end-user's machine hardware and network capacity.  If while watching the video the machine or network conditions change, Silverlight can automatically switch to a more appropriate bit-rate without any buffering or interruption glitch.

Silverlight's support for adaptive streaming is extensible - which enables anyone to plug-in their own logic to control where the media content comes from, and what bit-rate should be used.  This means that any CDN or media delivery provider can easily integrate their systems with Silverlight and deliver super high quality video delivery.

Content Protection

Beta2 includes DRM content protection, and supports Windows DRM and PlayReady DRM.  Both work cross browser and cross platform.

Server Side Playlists

Beta2 adds support for server side playlists (previous releases only supported client-side playlists).