"My approach would be to partner as broadly as possible with anyone who is in this business," Nadella said.

While Nadella oversees Windows Server and Windows Azure, Microsoft's cloud ambitions extend much further with , a hosted version of Exchange, SharePoint, Lync and Microsoft Office. Office 365 is set to launch , while its predecessor, the BPOS service, just before Nadella took the stage.

Office 365 isn't Nadella's responsibility, but he was willing to admit something other Microsoft executives try to avoid discussing: Office Web Apps, the online versions of Word, PowerPoint and Excel, are limited.

"They're pretty good, but they're not as good as the Office client is today," Nadella said of Office Web Apps.

Regarding Azure, Nadella pitched Microsoft's ability to offer both public cloud services and the software necessary to build private clouds. The has allowed customers like Fujitsu and eBay to bring Microsoft cloud technology into their own data centers, he said. Fujitsu, for example, turned to the Azure appliance when it came to putting mainframe in a cloud service.