Docker containers are like VM's but smaller. I think what it means is that a Windows server / VM will be able to run dozens-hundreds of Windows micro-services inside a Docker for Windows infrastructure. Or basically once finished you as a developer can now write Windows apps that don't need to install and will run on any Windows, no more version dependencies! Just like Docker is doing for Linux today.
Yeah, but wouldn't it have to be rewritten from scratch on Windows? AFAIK there is no chroot, cgroups or anything like that in Windows (I guess there might be equivalents). And I have no idea what you would do about the registry blob in this scenario.