The February CTP of WinFX has been released, and there are a couple things worth immediate notice for this audience:

  • The extension of XPS Documents has changed to the final .xps from .container. If you are generating files with the Office "12" Beta 1 or have other pre-existing content, you'll need to update the extension. The XPS Viewer understands this extension too! 
  • The namespaces, content types, and relationship types have changed. As documented in 0.8 as a forthcoming change, the Open Packaging Conventions namespaces, content types, and relationship types have been updated.

These are probably the 2 biggest changes you'll notice as you work with XPS Documents generated prior to the CTP.