Playing audio files in Silverlight is non-trivial. Hence, the need for a library that allows you to do so; so this is another Tools update to include an AudioManager Silverlight-only class.
What does it do? It allows you to play files, loading them on-demand as necessary; it also allows you to explicitly load (and preload) all sound files, or even load all sounds in a directory. And it builds on the back of our embedded resource classes, so it handles all the crazy resource stuff that drives you crazy, like your path having slashes instead of dots, or underscores.
So enjoy! You can hit up the Tools library page to find the API details.