I've worked in I.T. literally forever. Docker is "the new black".
I would imagine that VMs will be gone in ten years, completely replaced by Docker images. The underlying technology under Docker is the Linux Container (LXC) as seen in Ubuntu MaaS's implementation of OpenStack. I once took thirty recycled Dell Vostro 200 computers and built a private cloud with them for no purpose other than to see if I could.
Imagine running one Juju bundle and each of those icons below is a separate LXC as created as separate components on one of four of those computers each turned into cluster nodes and available for provisioning. It takes about twenty minutes' running time but the components are provisioned from these pre-canned images. At the end of all this, you have something that works just like
openshift.com for spinning up servers and S3 buckets in the cloud.
In short, LXCs (Docker) is the technology that will be worth something in the future as a skillset to possess.