I've converted a couple of VirtualBox images over to qcow2 to use with Qemu. While Qemu works just fine, for desktop use AQemu looks to be a nice GUI for launching the various VMs.
After firing it up I figured that setting it up for an existing Qemu disk image would be straight forward but all I can see is a wizard for creating a new disk image.
It seems that I'm missing something obvious.
My Google fu led me here.