The current demand for virtualization is, to a significant degree, an attempt by admins to get control of their own hardware back from Microsoft. Putting MS back in charge of the lowest layer hypervisor seems like it could sort of defeat the purpose. Or maybe they'll play nice this time?
What do you mean?
Interestingly, I view the current state of the world as too much sharing -- VMs are just super process isolation =D
It turns out that one of the apps people really need to run multiple instances of is Windows itself. This is largely Microsoft's fault for bundling every app including the kitchen sink in the OS platform itself. As a condition of using their clean little high-performance kernel, you had to accept a web browser and home-user-friendly userspace.
Little surprise that people are kicking the whole package off of Ring-0 and substituting something like vmware for their $five-figure server hardware.
It's that super-isolation that actually allows multiple apps/roles/data categories to finally share the same hardware.
This tradition started ~98, with Microsoft. Before that, when servers were Suns, IBM and Digital, every server had lots of roles.
Somehow, microsoft convinced the world that it's better to have one server per role (and pay them for some more licenses).
We should be virtualizing the software, not the machines. Oh wait, we already are: JVM, CLR, Python RT, good-old-fashioned processes etc...
Virtualization is just snake oil. I don't see a real use for it TBH and I work at a place that drinks the VMware kool aid. All it does is cost money, use up resources and excuse incompetant administrators from having to plan properly up front.