I have been able to get a litle further with converting a windows VM.
After getting the updated virt-v2v code and rhsrvany, I now get this error:

libguestfs: trace: hivex_node_set_value = 0
libguestfs: trace: upload "/usr/share/virtio-win/drivers/amd64/Win2012R2/netkvm.cat" "/Windows/Drivers/VirtIO"
guestfsd: main_loop: proc 365 (hivex_node_set_value) took 0.01 seconds
guestfsd: main_loop: new request, len 0x44
guestfsd: receive_file: reading length word
libguestfs: got daemon cancellation
guestfsd: receive_file: got chunk: cancel = 0x1, len = 0, buf = (nil)
guestfsd: receive_file: received cancellation from library
guestfsd: error: /Windows/Drivers/VirtIO: Is a directory
libguestfs: trace: upload = -1 (error)
libguestfs: trace: hivex_close
guestfsd: main_loop: proc 66 (upload) took 0.03 seconds
guestfsd: main_loop: new request, len 0x28
hivex: hivex_close: hivex_close
guestfsd: main_loop: proc 351 (hivex_close) took 0.00 seconds
libguestfs: trace: hivex_close = 0
virt-v2v: error: libguestfs error: upload: /Windows/Drivers/VirtIO: Is a
directory