Microsoft Monday unveiled two licensing options for Windows Vista Enterprise targeted at helping large companies centralize their desktop management.

The options, which are only available to users with Software Assurance contracts, include support for diskless PCs and the ability to run Vista within virtual machines on server hardware.

Microsoft says the licensing options at this time are likely to appeal only to very large IT shops and admits that the deployment options are for early adopters. The company hopes to use the next 18 to 24 months to gather feedback and tune the options, says a Microsoft spokeswoman.

The two options are: the right to use Windows Vista Enterprise on diskless PCs; and Windows Vista Enterprise Centralized Desktops (VECD), a subscription license to use Windows in virtual machines centralized on server hardware.

A company statement calls the deployment scenarios, “nascent technologies and new architectures” and acknowledges that “only a select few customers are planning to broadly implement these centralized desktop models today.”

But the options seem to be a setup for the future to align licensing and new virtualization technologies that are central to Microsoft’s emerging management platform as laid out last week at its annual Management Summit.

Later this year, the company will release System Center Virtual Machine Manager, which helps increase physical server utilization, and centralize management and provisioning of virtual machines. In addition, Microsoft plans to release in mid-2008 its hypervisor technology, code-named Viridian, which will run on the forthcoming Windows Longhorn Server. Longhorn includes a feature called the Terminal Services Gateway that will let users remotely access both their Terminal Services and VECD desktops.

“This seems to be preparation for impending wave of desktop virtualization,” says Andi Mann, an analyst with Enterprise Management Associates in Boulder, Colo. “Our research shows this as a rapidly growing area of virtualization -- with a predicted growth rate higher than server, application, or operating system virtualization.”

VECD is similar to Terminal Services, but Microsoft says the latter, well-established technology is a better choice for most users.