Hey, Parallels, Please add native support import VM from .ova container. Even VirtualBox support it for free. You KB suggest to download ovftool from VMWare, but full registration needed to download this tool.
These are open standards that allow appliances to be shared by developers so that users can use whatever virtualisation software they have. I recently downloaded an appliance in OVA format and wanted to run it in Parallels Desktop which turned out to be very complicated due to the lack of support. I ended up moving one of My Mac's to VirtualBox partly because of the lack of interoperability with Parallels and other virtualisation software. With the addition of an export option Parallels Desktop could become an option for appliance developers to run on their systems instead of VMware or others.