At a high level, it is easy to call the proliferation of virtual machines “sprawl” which connotes a negative use of resources. I think there is subtly here that implies not all this "sprawl" is actually bad.
In the past, to harness and use significant computing power in your office required lots of space, physical servers, power, cooling, time, server administrators, paper work etc. The bar was pretty high to get a brand new multi-thousand dollar server approved through the CFO. Once approved, you had to wait a significant period of time for server deployment on the data center floor. The cost, the process time, and the process steps were all long and complex. Only applications with the highest ROI and criticality theoretically made it through the gauntlet.
Virtualization has effectively lowered the cost, time and process bar to deploy a server. This is not all bad. In fact, it is the opposite. It means more and more computing power can be effectively deployed by an organization to its competitive advantage. Take the mainframe to open systems change. With the mainframe, only the crème de la crème of applications were deployed. The rest were done, well, manually. Open systems changed that and lowered the bar for application deployment and hence the ability to deploy compute power. We are seeing a similar change today with virtualization. The bar is lower and more compute power can be deployed to solve a company’s problems. That is a good thing. Hence I am not sure sprawl is the right term for these applications.
To learn more and to read the entire article at its source, please refer to the following page, The Bright Side of VM Sprawl- VKernel Blog