Using the Release preview of windows 8 trying to build anything exported from Construct 2 using the Windows 8 Metro App option gives the following error in Visual Studio:
Error 1 Could not find SDK "Microsoft.WinJS, Version=0.6". C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets 1682 6
This error was not present when using the Consumer Preview.
Problem Exists when using r90 and r93.