Next generation of Virtual Data Center will be in the roadmap by VMware latest press release.

http://www.vmware.com/technology/virtual-datacenter-os/

Here you can have more information about the next generation virtualization.

My personal point of view, this had been something we are looking at for quite sometime. It will be really nice that we could virtualize the data center, with the combination of cloud computing concept cum the virtualize data center together. As more and more application including messaging, ERP, Web hosting are adopting to virtualize, I believe the virtual datacenter will able to simplify and provide better way of managing the next generation enterprise computing.

Not sure when the Beta test will be started, but I will be more than happy to be enrolled if possible.