For example, VMware DRS, a tool that monitors the CPU and memory usage in a pool of servers to identify the most efficient place to run a virtual machine, still does not take into account other aspects such as I/O utilization.

And while Maritz talked about interoperability and the danger of "lock-in" from other cloud providers, vSphere cannot be used to manage hypervisors from Microsoft and Citrix Systems. VMware says there isn't enough demand for those platforms in the market yet to justify its investment to support them.

But some of its customers are using them today. Christopher Rence, CIO of predictive analytics company Fico, said his company has mostly standardized on VMware, but Fico is also piloting Microsoft's Hyper-V technology and will use it in some areas.