Business Insider
He just announced this at the Code Conference in Southern California.
On stage, an English-speaking Skype executive called up a German-speaking Skype executive.
They held a 5-minute conversation. The first executive would say something in English. Then, after a pause, the a computer voice would repeat what he said, but in German. Then the German executive would speak in German. After a pause, the computer spoke in English.
There were subtitles in both languages on the screen, too.
Nadella says the translator will be included in all Skype products across all platforms, including Skype's iPhone and Android apps.