You can download Windows Server 2008 Evaluation and Hyper-V RC1. The Release Candidate 1 (RC1) update to the Hyper-V role provides improvements to security, stability, performance, user experience, forward compatibility of configurations, and the programming model.
The idea that you can make pools of dynamic resources with unlimited capacity available to users anywhere at anytime is extraordinary. Virtualization is a means to enabling our long-standing vision of Dynamic IT, where people and computers get the resources they need the moment they need them.
Microsoft's virtualization products address customer needs from the data center to the desktop. For the data center, we offer Microsoft Virtual Server and we recently announced beta availability and the upcoming launch of our enterprise-quality Hyper-V hypervisor, which will be a key feature of Microsoft Windows Server 2008. On the desktop side, Microsoft Terminal Services virtualizes the presentation process, and Microsoft Application Virtualization lets you run applications without installing them on desktops.