Fortunately, the format if question is an open specification[1], so you can use a[2] number[3] of[4] tools[5] to convert the OVF to an interim format.
That is, obviously, a pretty ugly workaround.
[1] http://en.wikipedia.org/wiki/Open_Virtualization_Format
[2] http://www.vmware.com/support/developer/ovf/
[3] http://www.citrix.com/english/ss/downloads/details.asp?downl...
[4] http://www.virtualbox.org/manual/ch01.html#ovf
[5] http://www.microsoft.com/en-us/server-cloud/system-center/vi...