Virtualization is sometimes considered important because it may provide OS features that certain operating systems have failed to provide in the past, e.g., sep

Virtualization is sometimes considered important because it may provide OS features that certain operating systems have failed to provide in the past, e.g., separation of code/data areas, efficient utilization of resources, security, etc. And you _can_ run multiple OSs on one physical machine. See http://www.virtual-strategy.com/Features/Why-Virtualization-Matters.html http://www.virtual-strategy.com/Features/Why-Virtualization-... and use Google for more. Honestly I would be happy to find an OS/hardware combination that did everything they _should_ do (short of an IBM mainframe). As it is, virtualization is a meta-OS layer that is just waiting to be hacked/cracked.