Today Citrix released a windows only OVF management tool.
Here's how they describe it.
Citrix Project Kensho provides administrators with highly usable tools that facilitate the export and import of virtual machines and virtual machine based workloads (virtual appliances) using the Open Virtual Machine Format (OVF) and Common Information Model (CIM) industry standards developed by the Distributed Management Task Force (DMTF).
The Project Kensho OVF Tool utilizes the OVF standard for the export and import of virtual appliances. The Open Virtual Machine Format is an XML document that describes the metadata of virtual machine(s) that are stand alone or part of a virtual appliance along with pointers to the location of the virtual disks.
Citrix Project Kensho also provides a CIM interface to the XenServer™ API. As well as introducing a WSMAN interface to XenServer™. The Xen-CIM component is required by the Project Kensho OVF Tool and installs directly on the XenServer.
More Details > http://community.citrix.com/display/xs/Kensho