Though I wonder how much of it is really VMware specific, or if it would be relatively easy to port to Xen, etc.
Edit: actually it appears it might be agnostic to the virtualization layer.
Their core business today is selling vSphere 4 management with ESXi as the hypervisor, I think they see their core business in 10 years as being the management layer for your entire IT infrastructure, wherever it runs.
ESXi is excellent, I think one of the best x86 kernels in existence. The management software is nowhere near on par with it; it is finicky Windows software that doesn't match the hypervisor's speed or reliability. The long-rumoured Linux version of the management platform still has not materialised.