The update to Office 2008, now version 12.2.6, plugs a security hole that would allow potential hackers to access your Mac's data by overwriting memory with malicious code. The update is recommended for all users of Microsoft Office 2008 for Mac (Home and Student Edition, Special Media Edition, Student and Teacher Edition, and Business Edition).
The update for Office 2004 also provides security upgrades as well as continued stability improvements. It is recommended for all users running Microsoft Office 2004 for Mac (Standard Edition, Student and Teacher Edition, and Professional Edition).
Microsoft also released an update to Entourage 2008 for Mac, Web Services Edition containing improvements to calendar functions and includes the ability to sync notes, tasks, and categories with Exchange Server as well as log in remotely to perform diagnostics.