The Windows Virtualization Team blog includes a detailed post covering the Release To Manufacture of System Center Virtual Machine Manager (SCVMM). You can download a trial of the released version here.

SCVMM is cool as it enables you to dynamically manage your virtual workloads across multiple physical machines. You can choose to either provide maximum performance by spreading the virtual machines across all available physical machines, or reduce the number of physical servers you need (hence power/heat/cost) by loading as many virtual machines as possible on each physical server.

SCVMM uses System Center's capacity planning capabilities to measure the CPU, I/O, RAM and Network bandwidth requirements of each virtual machine to determine the best way to consolodate onto physical machines. SCVMM uses the same approach to recommend good candidates to convert from Physical machines to Virtual machines - it can then go ahead and perform the P2V operation for you. 

All of the operations you can instantiate from the GUI are actually executed by Powershell scripts hence you can easily customise and automate operations even further if you wish.

There has been a great deal of discussion over recent months within Microsoft over the proposed licensing scheme for SCVMM as those of us who work with Small and Medium Enterprises (SMEs) wanted a version that would suit their needs. In January (according to the team blog) a Workstation edition of SCVMM will be made available that will enable customers to manage up to 5 physical virtual server host machines.

The plans going forward are exciting too as the next version "...planned to coincide with the release of Windows Server Virtualization..." will be able to manage Virtual Server (Windows Server 2003), Windows Server Virtualization (Windows Server 2008), Xen (LINUX) and VMWare too!