I've use ovftool to create an .ova of a VMWare guest (in this case W2012), and then have converted it with virt-v2v, outputting to the oVirt export domain (virt-v2v -i ova /space/w2012-test.ova -o ovirt -os ovirt-engine:/mnt/export-vm -of qcow2). This appears to work, though it reports a warning:

[   0.0] Opening the source -i ova /space/w2012-test.ova
[   5.3] Creating an overlay to protect the source from being modified
[   5.9] Initializing the target -o rhev -os ovirt-engine:/mnt/export-vm
[   6.1] Opening the overlay
[  11.5] Inspecting the overlay
[  12.6] Checking for sufficient free disk space in the guest
[  12.6] Estimating space required on target for each disk
[  12.6] Converting Windows Server 2012 Standard Evaluation to run on KVM
virt-v2v: warning: Neither rhev-apt.exe nor vmdp.exe can be found.  Unable
to install one of them.
virt-v2v: warning: there is no QXL driver for this version of Windows (6.2
x86_64).  virt-v2v looks for this driver in /usr/share/virtio-win

The guest will be configured to use a basic VGA display driver.
virt-v2v: This guest has virtio drivers installed.
[  13.5] Mapping filesystem data to avoid copying unused and blank areas
[  16.6] Closing the overlay
[  16.6] Checking if the guest needs BIOS or UEFI to boot
[  16.6] Assigning disks to buses
[  16.6] Copying disk 1/1 to /space/scratch/v2v.F5dkB2/ff68b458-3fe9-4ecf-95b7-cfdcc42dd291/images/b8a180eb-e075-44bf-a6f0-263e2792f5d7/a49bed7d-9ac3-48f1-8b00-2abb1e4c183f (qcow2)
    (100.00/100%)
[ 200.3] Creating output metadata
[ 200.3] Finishing off