Download the Microsoft WinFX SDK Beta 1
The Microsoft® WinFX™ SDK contains documentation, samples and tools designed to help you develop managed applications and libraries using WinFX, which is the set of next-generation managed APIs provided by Microsoft. This release includes documentation about using the .NET Framework 2.0, the Windows Presentation Foundation (formerly code named “Avalon”), and the Windows Communications Foundation (formerly code named “Indigo”).
Download it here.