This is a shocker. Steven Sinofsky, the prickly but super-efficient executive famous for delivering big products on time for a company not known for meeting production schedules, is leaving Microsoft (s msft). Now. His departure comes just a few weeks after the debut of Windows 8, the massive project he led.

The news was reported by AllThingsD‘s Ina Fried. Sinofsky’s role will be taken over by — get this — two women. Tami Reller who will take on the business side of Windows and Julie Larson-Green will direct Windows software and hardware engineering, according to a Microsoft statement. Larson-Green had worked with Sinofsky for some time.

For years Sinofsky headed development of Office, Microsoft’s juggernaut desktop productivity suite. His success there led to him taking over Windows after the Vista debacle.

Jeff Raikes, then the Office guy at Microsoft, has lauded Sinofsky to me repeatedly over the years. Sinofsky…