Microsoft Hyper-V Server 2008 now available
I've been using Windows Server 2008 w/ Hyper-V for months now to host internal development systems; virtualization is letting me experiment with both test and production Windows Vista SP1 and XP SP3 images for doc writers, as well as with providing safe places to host development tools.
Now, just as I'm getting ready to migrate my Hyper-V environment to a new box, we've released the new Hyper-V Server 2008 product; the download site just went live today. Hyper-V Server 2008 is a simplified hypervisor; it lacks a GUI, and uses only the core set of Windows Server features needed to provide support for drivers, patching, and remote management. For my development and desktop virtualization needs, it's perfect.
How do you decide between Windows Server 2008 w/ Hyper-V and Hyper-V Server 2008? The Hyper-V Server 2008 site has more guidance.