Following the release of Windows 10 PC build 10166 today, Microsoft has pushed out an update to the Windows 10 Preview SDK for developers. While there isn't much new in this preview, it does bring along some bug fixes and an API change.
As far as what's new in this build, we're looking at mostly bug fixes along with the following API update:
Windows.ApplicationModel.Email - Additional getter properties added
Though the changes are minor, the updated SDK contains a known issue that will affect users upgrading from older builds 10069 or 10074:
When installing the Windows SDK 10 version 10166, an error that AppVerifier did not install correctly and setup rolls back OR When trying to uninstall Windows SDK 10 version 10069, an error that the AppVerifier package failed to uninstall.
Download AppVerifier.zip file to your PC.
Extract the contents to a known location. Example: C:\temp
From an Administrative command prompt, run c:\temp\InstallAppVerifierBinary.cmd
Once complete you should be able to install or uninstall the AppVerifier binaries.
And there you have it. Microsoft said in late June that it would start pushing new SDK releases out with Fast ring builds, and so far it has kept up with that promise. If you're an interested developer, you can download the updated SDK from the Windows 10 Developer Tools page now.