Securiteam blogs has published an excellent security guide for hardening Microsoft’s Hyper-V virtual environment
Windows 2008 R2 Hyper-V security Hardening Guide
QUOTE: Virtual Machine Servicing Tool 3.0 helps to update offline virtual machines, templates, and virtual hard disks with the latest operating system and application patches. Authorization Manager provides a flexible framework for integrating role-based access control into applications. It enables administrators who use those applications to provide access through assigned user roles that relate to job functions.