DISMTools is a front-end for DISM that lets you manage your Windows Imaging (WIM) files and a whole lot more.

Key features
DISMTools is the first project-based GUI. Projects store the mounted image and unattended answer files you want to apply (using the command line at this time), while also providing a scratch directory for temporary operations
DISMTools is also smart, checking first if an action can be performed before doing it