What we need is a utility that converts a Hyper-V VM’s virtual hard disk to a container.
Such a utility already exists for VMware VM’s virtual hard disks.
Hey, Microsoft, are you going to take the insult and let this pass?
Update (May 13, 2017): So, there does exist a way to convert Hyper-V virtual disks into Docker containers: Image2Docker. I stand corrected. Please refer to Working with Windows Containers and Docker: Into your Stride