Good news – new ISOs can be downloaded now from two locations. Windows Insiders can grab the latest ISO for Windows 10 Pro from http://windows.microsoft.com/en-us/windows/preview-iso-update-1504, and for those wanting to check out the Enterprise edition you can grab that from the Evaluation Center at https://www.microsoft.com/en-us/evalcenter/evaluate-windows-enterprise-insider-preview. For those on the fast ring for updates you should see this build come through soon, and a new version of the Assessment and Deployment Kit should be available soon. More details available at http://blogs.windows.com/bloggingwindows/2015/04/29/new-windows-10-insider-preview-build-10074-now-available/.
Over on the Microsoft Deployment Toolkit Team Blog they have posted some information about some issues wit h Windows 10 Technical Preview builds having some issues with the MDT 2013 Update 1 Preview. Check out the article to see the full workaround, which includes the following steps. Download the MDT1503.zip file which includes updated scripts and xml files Grabbing the latest version of the Windows ADK for the Windows 10 Technical Preview Using the correct version of Windows PE Fixing