We've been waiting for these! The just-released fixes a variety of troublesome bugs, some introduced in the previous update. And, the  fixes some crashing bugs, improves compatibility with Mac OS X 10.5 Leopard, and includes all the updates previously released for Office 2004, so new installations of Office 2004 don't have to be updated 19 times to be brought up to date.
Office 2008 Changes -- Most notably (from my perspective, anyway), Word and Excel documents downloaded from the Web or attached to email messages will now open when double-clicked. Yay! This has been driving me bonkers whenever I tried to open a Word file attached to an email message in Eudora.
Also fixed in Word 2008 is a bug that would cause spaces to be lost when opening a document created in or saved by Word 2008 or Word 2007 in Windows - I didn't run into that one, thankfully. Other fixes preserve items in Notebook Layout documents when the document is converted from .docx to .doc, preserve font size settings for text in tables, and address a problem in saving .doc documents that contain an Area or Filled Radar chart.
Excel 2008 also features numerous improvements, including accepting international decimal separators for error bars, no longer duplicating embedded movies when workbooks are saved in .xls format, and improving PivotTable reports. Excel's reliability has been enhanced in a variety of situations, such as when chart data is updated, when you reference or link to a sheet name that resembles a cell reference, and at times when you calculate or edit a formula.
PowerPoint 2008 and Entourage 2008 see fewer changes. This update fixes a problem that would cause PowerPoint to take a long time to open presentations that use certain fonts, and also fixes a nasty bug that would cause Entourage to crash when you wake the Mac from sleep.
The Microsoft Office 2008 for Mac 12.1.1 Update requires Mac OS X 10.4.9 or later, and that you have already installed the Microsoft Office 2008 for Mac Service Pack 1 (see "," 2008-05-19). It's a 153.3 MB download, and is  or via the Microsoft AutoUpdate utility launched by choosing Check for Updates from any Office 2008 application. Once again, kudos to Microsoft for excellent release notes.
Office 2004 Changes -- For Office 2004, which Microsoft appears to be maintaining more actively than is usual for a previous release, the 11.5.0 update improves compatibility with documents in the Open XML format used by Office 2008 and Office 2007 in Windows, and it also fixes a problem whereby the installer would find copies of Office backed up by Time Machine.
In Word 2004, Microsoft fixed a number of crashing bugs, including several that could occur during typical operation, one that could happen when you pasted content from an Office 2008 document into Word 2004, and one that kicked in when getting the properties of a hyperlink via AppleScript. Other fixes include improved text display when you change the size of table columns and cosmetic improvements to the Page Setup dialog in Leopard.
Similarly, Excel 2004 receives fixes for errors when pasting data from Excel 2008; for crashing bugs related to opening workbooks containing a shape, a SmartArt graphic, or a text box created in Excel 2008 or Excel 2007; for saving paper sizes for documents saved in both Excel 2004 and Excel 2008; and for the inability to open Excel 2007 documents via the Open dialog.
Finally, the update fixes a problem in PowerPoint 2004 that could cause crashes when opening presentations with a large number of slides, or when pasting content from an open Office 2008 application running on an Intel-based Mac into a PowerPoint 2004 presentation.
The Microsoft Office 2004 for Mac 11.5.0 Update requires Mac OS X 10.2.8 or later, and as I noted previously, includes all previous Office 2004 updates. It's a 58.9 MB update, and is available either via the Office 2004 version of Microsoft AutoUpdate or as.