Key Features of Hyper-V
Quick migration
Enables movement of running virtual machines from one host to other host servers with minimal downtime.
High Availability
Hyper-V includes support for host-to-host connectivity and enables you to cluster all virtual machines running on a host.
Live Backups with VSS
Hyper-V includes support for Volume Shadow Copy Services (VSS) to enable you to take Live Backups of running virtual machines in terms of snapshots.
Improved performance
Hyper-V includes several fixes to improve performance. All new Windows Server 2008 virtual machines will now automatically include the integration components.
Increased Memory Support
Hyper-V supports up to 64GB of memory per virtual machine.