The Windows SDK for Longhorn Beta3 is posted. You can download it from Windows SDK for Windows Server code name “Longhorn” and .NET Framework 3.5.
The official word:
This release of the Windows SDK is designed to operate with the matching Windows Server code name “Longhorn” Beta3. The SDK is compatible with the RTM release of Microsoft® Visual Studio® 2005 SP1; including Express Editions of Microsoft® Visual Studio®. It ships the VC++ SP1 compiler and associated CRT.
As always, please look over the Release Notes for a description of known issues with the SDK. One very important item from the Release Notes is that this release of the SDK is an ISO-only download (details about this are available at the SDK download page).
Another item of interest relates to the second part of the SDK’s name; specifically .NET Framework 3.5. The SDK not only ships content aligned with Windows Server code name “Longhorn”, but also content that aligns with the upcoming .NET Framework 3.5. The .NET Framework 3.5 is available with of the Beta1 pre-release editions located at Microsoft® Visual Studio®, Code Name "Orcas" Downloads and is required in order to take advantage of any tools or samples that have a dependency upon the .NET Framework 3.5.