Hot on the heels of the release of the Expression Encoder, Ben Waggoner has worked on some training videos that were produced by Total Training that have now been released.
Here are the links
Introduction to Expression EncoderEnhancing MediaMetadata, Markers, & SilverlightLive ProductionAdvanced Expression Encoder
and you find lots more training of other products in the Expression suite on the Microsoft Expression Training page.
Also Channel 9 has another Expression Encoder video with our own James Clarke and Jim Thill