Microsoft recently released the consumer preview new version of Office; Office 2013 back on July 16th as a consumer preview. Office 2013 has a metro UI which is similar to what Windows 8 has (See: Office 2013 Screenshot Tour) and has several new features including tight cloud integration (Read: Office 2013 Features).
Also Read: Use Word 2013 to Edit Your Blog
However, less than a moth later, Microsoft has now released an update to Office 2013 which updates the version to 15.0.4128.1019 from the earlier version 15.0.4128.1014. However, there is no change log available for the update and I am still trying out figure out the changes in this release.