Yes I understood that. But right now if you want to use docker.io on your OSX dev box you have to run linux inside a VM to be able to leverage the docker.io features (building and testing apps in lightweight containers) for later deployment on the target cloud infrastructure.
If you have OSv working both under virtualbox or vmware on your OSX dev box and under KVM or EC2 HVM on your cloud production environment, then it might be possible to have a docker.io features directly under your OSX dev box.
docker is more like a frontend to pack, ship and deploy specific applications and their configuration as "containers" to be run in lightweight isolated environments (such as LXC currently).
Currently if you want to use docker under OSX you have to run it inside a Linux VM (typically using the vagrant / virtualbox). But the Linux VM is using a bunch of memory on your dev environment. If docker could run the app inside virtualbox + OSv rather than having to use virtualbox + full linux + LXC I assume you would get a more lightweight dev environment (faster boot times and less memory usage).
If you have OSv working both under virtualbox or vmware on your OSX dev box and under KVM or EC2 HVM on your cloud production environment, then it might be possible to have a docker.io features directly under your OSX dev box.