On 6/16/11 Microsoft released updates for Office 2011 (14.1.2), Office 2008 (12.3), and Office 2004 (11.6.4). These updates patch security issues, plus provide bug fixes for Word 2011 and Outlook 2011.
Based on my research I’d say it’s safe to apply these updates. The only issue I uncovered was with the Office 2011 update, where you may receive an error stating “Office 2011 14.1.2 Update can’t be installed on this disk. A version of the software required to install this update was not found on this volume”. If this occurs, manually download and apply the Office 2011 Service Pack 1 (14.1.0) updater first, then run the 14.1.2 update again afterwards: http://www.microsoft.com/mac/downloads