I just finished writing all the content for my next book entitled VMware ESX and ESXi in the Enterprise: Planning Deployment of Virtualization Servers (2nd Edition) which continues the discussion on Dynamic Resource Load Balancing (DRLB). DRLB is the balancing of virtualized workloads across all hosts within a cluster of virtualization hosts without human intervention. This is the ultimate goal of automation with respect to virtualization and therefore the cloud. In effect, with DRLB the virtualization administrators job has been simplified to configuration and trouble shooting leaving the virtual environment to load balance work loads on its own.
This is a lofty goal, and we are not quite there yet, but we are further along than when I wrote VMware ESX Server in the Enterprise: Planning and Securing Virtualization Servers when ESX 3.0 first shipped. But what has really changed, as I talk to people, much of the automation is still done by hand coding specifics to all environments. I think we are close, and take some of the real innovations as writ and move on from there.