Shortly after Visual Studio 2010 ships the Windows 7 SDK will be updated to include the development tools, samples, and resources for .Net 4. The current version of the SDK is for Windows 7 and .Net 3.5 SP1. The native portion of the SDK will have a small number of improvements but mostly will be the same as the original Windows 7 SDK release.
For .Net 4 you’ll get all of the assemblies, framework tools, libraries, and headers that come with Visual Studio 2010. This allows you to develop for .Net 4 without having Visual Studio installed. As a change from past releases though, the SDK will not include the .Net 4 framework samples. Instead, the samples will be available as a separate online download from MSDN. This change will greatly shrink the size of the SDK download from multiple gigabytes to having a complete install that fits on a single CD.
You’ll need to have the full and final version of .Net 4 installed prior to being able to use the SDK. I’ll put up a download link once it’s available.