Jason Sacks on Monday August 8:
We’re just finishing signoff today on the Windows SDK. You may have seen this product referred to as the Longhorn or Vista SDK, but this release encompasses both the WinFX docs and Vista-specific documentation. The SDK, with samples, tools and docs, will be available as a download for MSDN subscribers, so subscribers, watch your mail. The docs will also be available online in browsable form in the same way that the WinFX docs are, and those docs will be available for everyone. Expect that to be online shortly.
After that we’ll start ramping up for PDC in Los Angeles in mid-September.
Per the comments to the post, Windows SDK = Platform SDK + WinFX SDK . The PDC is scheduled for September 13-16 in Los Angeles.