Mike_Laverick says Multi-Hypervisor Manager (MHM), as you might know there’s been a “Fling” on the VMware Labs for sometime, that allows you to manage Windows HyperV hosts from vCenter. That fling is going to be discontinued and supported in the web-client. It will be a free component with Standard vCenter and support Windows HyperV 2008, and will support Windows HyperV 2012 when it finally ships. It will have a little bit more functionality that the original fling – it will be able to create new VMs on the Windows HyperV host and will more seamlessly integrate with vCenter. PMHM will ship as service that you add to your environment if you need it.
VMware vCenter Multi-Hypervisor Manager 1.0 Release Notes
VMware vCenter Multi-Hypervisor Manager 1.0 | 19 Nov 2012 | Build 901315 | Product Download
This video was recorded at the VMworld 2012 Europe Barcelona and shows the Multi-Hypervisor Manager in action. (I'm the guy holding the microphone asking nasty questions :-))