VMware CEO Pat Gelsinger is banking that network virtualization will be a bigger deal for the company than its bread-and-butter vSphere server virtualization lineup in the not-so-distant future.

He’d better hope so. As Gelsinger himself put it Wednesday, vSphere has 80% market share in corporate data centers, so there’s not that much room for growth there.

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Network virtualization pools networking hardware—routers and switches—and configures and manages it as needed with software. Basically, the smarts of the system comes from the software, not the individual hardware components.

“NSX is the next ESX,” Gelsinger told attendees of the Goldman Sachs gs Technology and Internet Conference in San Francisco on Wednesday. ESX is the company’s basic and hugely successful ESX hypervisor, the foundation of VMware’s vSPhere server virtualization franchise.

“This is a more important transition than vSphere was,” Gelsinger said, adding that the company seeks to double NSX customer accounts next year.

And, importantly, he reiterated what he said on the recent VMware vmw earnings call, which is that NSX will run on multiple clouds including Amazon amzn Web Services and Microsoft msft Azure, “not just VMware-based clouds.”

Critics would say this is a good idea since there aren’t many VMware-based clouds, and AWS has built what looks to be a $10 billion-a-year business running computing jobs for paying customers. Many of those jobs in the past would have flowed to internal data centers running—you guessed it—VMware vSphere.

So much for that unified EMC-VMware cloud effort.

Like every other technology company from the pre-cloud computing era, VMware is under pressure to show that its new products can make up for declining sales of its legacy cash cows. NSX grew out of VMware’s $1.05 billion acquisition of Nicira, a network virtualization pioneer, in 2012.

Gelsinger noted that the company’s end-user computing group has surpassed the $1.2 billion annual run rate. The next business expected to hit that target? NSX, he said.

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Audience members were told there would be no questions about the one thing everyone really wanted to hear about: Dell’s problem-plagued acquisition of EMC emc , which owns a majority stake in VMware. Or the controversial VMware tracking stock that has been proposed as a part of that deal.

Too bad, there are certainly lots of questions there.