Microsoft has released updates for both Office 2008 (12.1.3) and Office 2004 (11.5.2). The updates provide a number of security, stability, and performance-related fixes. The security fixes primarily address file format and formula parsing vulnerabilities in Excel.
Microsoft Office 2008 for Mac 12.1.3 Update weighs in at 154.4 MB and addresses security vulnerabilities and increases stability and reliability throughout the suite of Office applications. The update also provides specific performance improvements for Word, Excel, PowerPoint, and Entourage. A full list of improvements is included on Microsoft's update description page.
Microsoft Office 2004 for Mac 11.5.2 Update weighs in at 13.3 MB and, in addition to addressing security vulnerabilities, fixes two reliability issues in Excel 2004 involving the "SUMIF ()" function and saving backups to network volumes. Microsoft's update description page details these improvements and provides additional information about the update.