The application is slated for release to businesses on 30 November, together with Windows Vista and Exchange 2007. The consumer launch is scheduled for early next year.
The productivity suite has been in beta since November last year and has since been downloaded by more than 3.5 million people, according to Microsoft.
The suite's main feature is a new user interface unveiled last year at the Professional Developer Conference in Los Angeles by Microsoft chairman Bill Gates.
The interface is designed to change with the task being performed, which Microsoft expects will better inform users of the available features.
Internal Microsoft research had shown that the features most requested by users were already available in the software but were difficult to find.
Office 12 will also offer new business intelligence tools to help employees find and analyse information.
J1043+2408 was observed for more than 10 years, and its radio light curve exhibited a periodic signal repeating in about 563 days
Success of Unity's test flight means Virgin Galactic is now close to taking its first paying tourist into space
V3 puts the pro-level football GPS tracker through its paces, and asks if it's more than a gimmick
Finding refutes many earlier studies that suggest that galaxies don't have much dark matter at the time of their birth