System Center Virtual Machine Manager 2008 R2 provides features that enable new management scenarios, address user concerns, and enable support for Windows Server 2008 R2. —from Rakesh Malhotra, Principal Group Program Manager
New features include support for the following:
Live Migration Management of the Live Migration feature of Hyper-V R2 for both planned and unplanned downtime scenarios.
Multiple virtual machines per LUN Utilizing the Cluster Shared Volumes (CSV) feature of Windows Server 2008 R2, VMM R2 allows multiple virtual machines to reside on the same CSV-enabled logical unit number (LUN). In this configuration, a virtual machine can be migrated independently from the others residing on the same LUN.
SAN migration in and out of clusters With VMM R2, you can migrate a virtual machine from one cluster to another, or from a stand-alone host into a cluster or vice versa.
Networking enhancements in Hyper-V R2 Hyper-V R2 provides support for TCP/IP chimney and Virtual Machine Queues (VMQ), reusing VMware port groups, and gives you the ability to enable/disable MAC spoofing on a per virtual machine basis.
Maintenance Mode VMM R2 supports the concept of host maintenance mode. When a managed host is put into maintenance mode and the host supports live migration, then the virtual machines are live migrated off the server to another host. If the host does not support live migration, then the virtual machines can be placed in saved state.
Disjoint Domains VMM 2008 R2 automatically creates custom SPN for DNS name when the host has a different fully qualified domain name in active Directory and DNS.