One of the things about Microsoft’s (MSFT) cloud computing strategy that isn’t always fully appreciated is the enormity of the ecosystem being built around Windows services in the cloud.

For example, with the recent addition of Rackspace to the number of cloud service providers running the same core Microsoft Cloud OS platform now extends to well more than 100 different companies.

Based on Windows Server 2012, the Microsoft Cloud OS platform provides a consistent set of IT services customers can invoke consistently no matter where Microsoft provides them via its Azure cloud platform or any one of more than 100 other cloud service providers.

In stark contrast to that ecosystem, the cloud services from Amazon Web Services, Google Cloud, IBM and others are only available via a single provider. Marco Limena, vice president of Hosting Service Providers at Microsoft, explains that a big part of the Microsoft cloud strategy is to leverage partners to apply a force multiplier effect across the cloud. That’s critical because no IT organizations want to be locked into a single cloud service provider, said Limena.

In fact, what most customers want is to be able to move workloads in and out of the cloud as they see fit. That means having the option of firing up a workload in the cloud and then having the option of moving that workload either back on premise or to another cloud as they see fit. Having a Cloud OS platform that provides a consistent set of application programming interfaces (APIs) across all those environments gives IT organizations the kind of flexibility they require, especially when they are trying to connect front-end services based on Microsoft Office applications running on premise or in the cloud to back-end services.

Naturally, not every workload in the enterprise is running on Windows. But clearly there is enough critical mass behind Windows inside the enterprise to make cloud services running a complete Windows server stack a preferred option for many customers. As Microsoft continues to build out that kind of hybrid cloud computing ecosystem, rival cloud service providers soon will discover how powerful Microsoft really is in the cloud. After all, it’s not just the Microsoft Azure cloud they are competing against—it’s really a set of cloud services that, over time, will become increasingly federated.

In the meantime, as the line between public and private clouds continues to blur, solution providers might want to start preparing for a world of hybrid clouds where customers are a lot more interested in flexibility than they are necessarily in any one particular cloud service. In fact, the real opportunity going forward actually may be providing the managed services that enable the federation of those services to occur.