Microsoft has just launched a beta of the the Microsoft Virtual Machine Converter Plug-in for VMware vSphere Client v1.0. The idea is that you can start the conversion of VMware virtual machines into Hyper-V virtual machines from a menu in the VMware admin tool 
The MVMC Plug-in for VMware vSphere Client Beta:
- Extends the vSphere Client context menu to make it easier to convert the VMware-based virtual machine to a Hyper-V-based virtual machine.
- Is built upon the Microsoft Virtual Machine Converter release candidate.
This plug-in extends vSphere Client to facilitate conversions from a virtual machine context menu and without changing configurations on the source VMware host. For more details about which guest operating systems are supported, see the Microsoft Virtual Machine Converter.