Product : VMware, vSphere/6.0, Enterprise Plus
Feature : Cross-Vendor Mgmt, General, Management
Content Owner:  Roman Macek
Limited (Free Add-On): Multi-Hypervisor Manager 1.1 ;
Yes (with Vendor Add-On: vCloud Automation Center)
vCenter Multi-Hypervisor Manager is a vCenter component that allows (basic) management of heterogeneous (currently translates to: Microsoft Hyper-V) hypervisors in VMware vCenter Server.
- VMware vCenter Multi-Hypervisor Manager is available to all vCenter Standard Edition customers as a free download
- vCenter Multi-Hypervisor Manager 1.1 is compatible with vCenter Server 5.1.x and 5.5 and vSphere Client 5.1.x and 5.5
- It is NOT available in the vSphere Web Client
- Number of supported third-party hosts has been improved to 50 (from 20) in vCenter Multi-Hypervisor Manager 1.1

As with any multi-hypervisor management the typical concerns remain: e.g. Delay of support for new versions (e.g. Server 2012), only subset of activities is supported, typically not allowing for the elimination of the native vendor tool.
Also, see this interesting article from Mike Laverick on real-life capability evaluation ...

Core Features (third party = MS Hyper-V):
- Third-party (MS Hyper-V) host management including add, remove, connect, disconnect, and view the host configuration.
- Ability to migrate virtual machines from third-party hosts to ESX or ESXi hosts.
- Ability to provision virtual machines on third-party hosts.
- Ability to edit virtual machine settings.
- Integrated vCenter Server authorization mechanism across ESX/ESXi and third-party hosts inventories for privileges, roles, and users.
- Automatic discovery of pre-existing third-party virtual machines
- Ability to perform power operations with hosts and virtual machines.
- Ability to connect and disconnect DVD, CD-ROM, and floppy drives and images to install operating systems.

With the addition of vCloud Automation Center, VMware has also multi-vendor cloud management capabilities. VMware vCloud Automation Center acts as a service governor, enabling policy-based provisioning across VMware-based private and public clouds, physical infrastructure, multiple hypervisors and Amazon Web Services.
VMware vCloud Automation Center is part of the vCloud Suite and is a fee-based add-on - see the cloud section for details.