VMware is still very secretive about the release of VDC-OS, only saying that it will be sometime in 2009. Pricing and packaging will also be announced later.

The company is one of a growing number of vendors that see future cloud computing as a hybrid between internal and external services running hand in hand -- which VMware calls a virtual private cloud, something that will be made possible by its vCloud Initiative.

CIOs won't have the luxury of being able to move internal IT systems to new cloud service providers, including Google and Amazon, according to Balkansky.

If VMware gets its way, software from the company will be used in both the internal and external cloud. At the same time, VMware says it wants to be a part of driving standards around cloud computing interoperability.

Standards will be very important to the future cloud computing. If standards aren't developed clouds run the risk of becoming a Hotel California, a place where you can check in, but never check out, according to Maritz.

At VMworld Europe, the company is adding an API (Application Programming Interface) to its vCloud Initiative. The vCloud API will allow the migration of virtual machines between a company's own infrastructure and another service provider and will also become part of VDC-OS.

The API is currently in a private release for VMware's vCloud partners. "Service providers would use the API to build their cloud computing services in a way that they import and export virtual machines from the on-premise infrastructures of customers," Balkansky said.

If a virtual machine is to be moved from one cloud to another, they need to speak a common language. Even if both sides are based on the same platform, the receiving cloud service provider needs to know what's running inside the virtual, about security policies and availability, according to Balkansky.

Management will be important to the success of both vCloud Initiative. At VMworld Europe, the company is adding a plugin to the VI Client -- the user interface of vCenter. It will allow administrators to see and manage all of the virtual machines, and it won't matter where they are running, Balkansky said.

He expects the adoption of the technology to closely mimic that of virtualization; starting with testing and development and then moving from there.

VMware also announced it is adding a high availability feature called vCenter Server Heartbeat to its central management console vCenter.

Heartbeat will provide a fail-over feature to the vCenter server itself. If something happens to the primary management server, a spare copy will take over without any downtime, Balkansky said.