Jeff Wolsey talks on the Edge about what's coming in the RC0 release of Hyper-V, described in this KB, including:

  • Perf improvements for VMs using pass-through disks will see a substantial performance improvement.
  • Installing Hyper-V VMs via network (RIS/PXE/WDS) is greatly improved.
  • Support for XP and Vista SP1 guests.
  • Partial localization in Japanese and German for testing in those languages.

As of today, you can get the RC 0 off WSUS, since it is a Windows Server 2008 patch. For more info see How to Install Windows Server 2008 Hyper-V Release Candidate.

You'll want to read the Release Notes for This Release of Hyper-V.

You can find the Hyper-V manager mmc here:

Vista x64 Edition: http://www.microsoft.com/downloads/details.aspx?FamilyId=450931F5-EBEC-4C0B-95BD-E3BA19D296B1&displaylang=en

Vista x86 Edition: http://www.microsoft.com/downloads/details.aspx?FamilyId=BC3D09CC-3752-4934-B84C-905E78BE50A1&displaylang=en

NOTE:  Virtual machines that were created on the beta version of the Hyper-V role do not start after the Hyper-V role is updated to a later version. You can use the virtual hard disk (.vhd) files. However, the virtual machine configuration settings must be re-created. Stepwise instructions are in KB 949222 (http://support.microsoft.com/kb/949222/)