Mesos is a form of virtualisation - just a different type.
I am not surprised HortenWorks customers are on containers / bare metal - the over head for their workloads that would be caused by a traditional hypervisor would be costly.
For single tenant DCs - there might be less virtualisation in coming years, but Mesos / Docker have not yet implemented the same layer of isolation that KVM / Xen / ESXi have, so we will still see (traditional) virtualisation in shared environments.
Also - Amazon / Azure / Rackspace are quite definitely not going to have it relegated as legacy.
I am not surprised HortenWorks customers are on containers / bare metal - the over head for their workloads that would be caused by a traditional hypervisor would be costly.
For single tenant DCs - there might be less virtualisation in coming years, but Mesos / Docker have not yet implemented the same layer of isolation that KVM / Xen / ESXi have, so we will still see (traditional) virtualisation in shared environments.
Also - Amazon / Azure / Rackspace are quite definitely not going to have it relegated as legacy.