Convert-WindowsImage is the new version of WIM2VHD designed specifically for Windows 8. Completely rewritten in PowerShell, this command-line tool allows you to rapidly create sysprepped VHD and VHDX images from setup media for Windows 7/Server 2008 R2 and Windows 8/Server 2012.
Download the tool from here
Going to try this out right now. Thanks for the script.