We have been working on adding Citrix Project Kensho OVF capabilities to XenConvert.
XenConvert is the free Citrix machine conversion utility. It is primarily focused on converting workloads to either Provisioning Server or to XenServer, however there are some more generic functions that are of interest to most any virtualization folk.
The download can be found here:
If this moves in the future go here: http://www.citrix.com/English/ss/downloads/results.asp?productID=683148 and look for XenConvert in the XenServer download section.
OVF packages from any existing VMware product (known to this date) can be consumed (imported) direct to XenServer.
The physical to OVF path can be run within a Windows machine and convert it to an OVF (meta file + .vhd) or just a vhd.
The OVF can then be consumed to XenServer with XenConvert 2 or to XenServer and / or Hyper-V in the upcoming Kensho refresh.
The VHD can, of course, be copied to any engine that uses vhd.
It also does a binary conversion of vmdk to vhd and injects a critical boot device driver that is compatible with XenServer (and works with Hyper-V).
Also, the XenServer .xva (vm backup files) can be converted to OVF.
Download and enjoy!