What it provides:
Bulk management of multiple VMs, Virtual Networks, Virtual Hard Drives, Snapshots, etc. within one Hyper-V servers and across multiple Hyper-V servers.
Support for remote management of Hyper-V servers using alternate credentials.
Integrated management of standard Windows features like Processes, Services, Event Logs, etc.
Automatic credential caching (in memory, not to disk) allowing you to enter a password for a Hyper-V server you are managing only once per PowerGUI session.
Discovery of Hyper-V servers through Active Directory.
Over 30 rich user-defined functions that wrap the Hyper-V WMI interfaces and provide a cmdlet-like experience when scripting with Hyper-V while outputting rich, custom objects complete with properties and methods to script to your heart’s content. Many of these functions support CSV input through Import-Csv, so there are a lot of opportunities for provisioning already available.
101 links and actions allowing you to manage just about everything you would want to manage in Hyper-V, including configuration of security via AzMan Scopes, Snapshot refresh, and many, many more.
Read more: http://poshoholic.com/2008/10/22/powergui-now-with-100-more-hyper-v/