imageExpression Encoder is an advanced audio/video-encoding and live-broadcasting application especially suited for generating content that takes full advantage of the rich graphic and interactive capability of Microsoft Silverlight playback scenarios. You can also generate Windows Media video and audio files that are optimized for other web playback scenarios, or appropriate for playback on portable devices.

Expression Encoder 4 SP2 provides support for Sandy Bridge graphics processors (Expression Encoder Pro with SP2 only), SRS audio, and adds the ability to manage publishing points, among other features, as well as bug fixes and stability enhancements. Also in this version, Expression Encoder Screen Capture no longer limits screen capture durations.

Go get the bits and details @ http://www.microsoft.com/download/en/details.aspx?id=27870.  More information @ http://www.microsoft.com/expression/products/Encoder4SP2_WhatsNew.aspx.