Over at the Windows Server Division Blog they finished a series of 3 postings today. Virtualization as a platform feature is now available as
Part I
"Server virtualization delivers flexibility that allows IT to respond to the business much more effectively. Once you have a workload, such as a business application, running in a virtual environment you have a lot more flexibility to manage that server. Additionally, you can deploy new servers, supporting new workloads, much more quickly."

Part II
"Windows Server 2003 R2 Enterprise Edition – Enhanced Virtualization Support
Windows Server 2003 R2 Enterprise Edition includes the use right for customers to run up to 4 additional virtual instances of Windows Server with one server license. This means that for roughly the same cost as 5 licenses of Standard Edition, customers gain the advantages of an enterprise-class platform. This includes increased headroom up to 8 processors (single or dual-core chips) and up to 64 GB of memory for the 32-bit version and 1 TB for the x64 edition, as well as the server clustering in Enterprise Edition.

Part III
"Putting it all together: There are several key scenarios that are now possible with server virtualization technology in the volume server space."
o "More Efficient and Rapid Development and Test"
o "Faster Deployment of New Servers and Quicker Rollback of Changes"
o "More Flexible Use of Hardware Resources and Disaster Recovery"