Hyper-V, one of the key features of Windows Server 2008, has now released to manufacturing (RTM) and is available for deployment into production environments. A beta of Hyper-V was included with Windows Server 2008 and this update provides the final release. The Hyper-V update will be available through Windows Update from July 8th.
I’ve upgraded my test lab running Hyper-V RC1 to the RTM version, and so far everything is running smoothly.
The official Press Release from Microsoft.