Windows Media Player 10 beta.

Help us test
the next-generation
Windows Media Player

Windows Media Player 10 is being refined to provide a great experience for discovering, playing, and taking your digital media anywhere. We are still in the early stages, but this technical beta lays the groundwork for the great end-to-end digital media experience coming with the final release of Windows Media Player 10, available for the Windows XP operating system.

For further details and for evaluation
http://www.microsoft.com/windows/windowsmedia/mp10/default.aspx#download