Microsoft today released a set of sample updates for XNA Game Studio developer education on App Hub. Several of your favorite samples and utilities have been upgraded to be compatible with XNA Game Studio 4.0.
In addition, a brand-new rigid-body and skinned animation sample is available for download:
Custom Model Rigid and Skinned Animation (New!): Import and play back animation files in-game, using custom 3D rigid-body and skinned models.
Samples, Starter Kits, and Utilities Newly-Upgraded to XNA Game Studio 4.0: